A Couple of Cuckoos (Japanese: カッコウの許嫁, Hepburn: Cuckoo no Iinazuke, "Cuckoo's Fiancé(e)") is a Japanese manga series written and illustrated by Miki Yoshikawa. It was originally published as a one-shot in September 2019, before beginning serialization in Kodansha's Weekly Shōnen Magazine in January 2020. An anime television series adaptation produced by Shin-Ei Animation and SynergySP aired from April to October 2022. A second season is set to premiere in 2025.
Plot
Nagi Umino is a 17-year-old second-year high school student who learns that he is not the biological child of the family that raised him. On the way to his first meeting with his biological family, he meets Erika Amano, a popular internet celebrity who is trying to escape from an arranged marriage. Later, Nagi and Erika discover that the hospital had accidentally switched the two after their births and their parents are now aiming to put them in an arranged marriage; so they, selfishly, do not have to say goodbye to the children they raised after missing out of their respective childhoods. To facilitate this, they are made to live in a house owned by Erika's family; hoping the two will fall in love before graduation, but will respect their wishes to abandon the idea if nothing comes of it.
A second-year student at Megurogawa Academy, who is ranked second in his grade. He is the biological son of a hotel tycoon, but due to a mix-up after his birth is raised by a different family. He has a crush on his classmate Hiro Segawa and aims to confess to her once he beats her in the school rankings. Following a challenge which he won, he starts dating Hiro. However, he starts to develop feelings toward Erika after realizing he hurt her by choosing Hiro.
A popular Instagram celebrity who is the biological daughter of the family that raised Nagi. She first meets him while taking videos at a park, and makes him pretend to be her boyfriend to escape from an arranged marriage, unaware that her parents arranged for her to be engaged to Nagi and for them to live together in a single house. After her school discovers the pictures she took with him, she is forced to transfer to Nagi's school. She decided to start an Instagram account in order to reach someone she had been looking for. Though she initially had no romantic feelings or interest in him, Erika later on realizes she really is in love with Nagi, as she is hurt when he chooses Hiro instead of her. She nevertheless continues to have feelings for Nagi's biological older brother Sōsuke, the person she was originally searching for.
Nagi's adoptive sister and Erika's biological sister. She is scared that Nagi will leave her, and later she runs away from home and moves to the house where Nagi and Erika are staying. Later on in the series, she decides to aim for enrolling in Nagi and Erika's school after graduating from junior high school. She also has feelings for Nagi, which grew after she learned they are not blood-related.
Nagi's classmate who is ranked first in her grade. She lives in a temple and works as a miko. She later becomes friends with Erika. It is revealed that she is also engaged to someone else. Though she wants Nagi to get together with Erika, it is suggested that she has developed feelings for Nagi as well. She sometimes shows yandere tendencies towards Nagi.
Ai Mochizuki (望月 あい, Mochizuki Ai)
Nagi's childhood friend, who moved to China as a child due to her father's work, and returns to Japan for Nagi. She is also a popular online singer. She has loved Nagi since childhood, to the point of decorating her room with pictures of him.
Miki Yoshikawa first published the series as a one-shot in Weekly Shōnen Magazine in September 2019, as part of a promotion in which she would publish three one-shots and readers could vote on which would receive a serialization.[10][11] The series began serialization in Weekly Shōnen Magazine on January 29, 2020.[11] The first tankōbon volume was released on May 15, 2020.[12] A promotional video for the series was released on June 11, 2020. The video was voiced by Yūma Uchida and Maaya Uchida, who are siblings.[2] As of November 2024, twenty-five volumes have been released.[13]
The series is licensed in digital format in North America by Kodansha USA.[14]
In April 2021, an anime television series adaptation was announced. It is animated by Shin-Ei Animation and SynergySP and directed by Yoshiyuki Shirahata, with Hiroaki Akagi serving as chief director, Yasuhiro Nakanishi overseeing series scripts, and Aya Takano designing characters.[3] The series aired from April 24 to October 2, 2022, on TV Asahi's NUMAnimation [ja] block.[b] It aired for two consecutive cours.[63] The first opening theme song is "Dekoboko" (凸凹, Rough) by Kiyoe Yoshioka, vocalist of the Japanese duo Ikimonogakari, while the ending theme song is "Shikaku Unmei" (四角運命, Square Destiny) by Sangatsu no Phantasia.[7][64] The second opening theme is "Glitter" by Sumika, while the second ending theme is "HELLO HELLO HELLO" by Eir Aoi.[65][66]Crunchyroll streamed the series outside of Asia.[67] A spin-off mini anime series titled Kakkō no Iikagen premiered on YouTube on April 28, 2022.[63]
On April 11, 2022, Crunchyroll announced that the series would receive an English dub, which premiered on May 7. However, the English dub of the series was produced in Coppell Studios in what was Funimation, which acquired Crunchyroll in August 2021 and Sony rebranded Funimation as Crunchyroll in March 2022.[68][4] On July 10, 2022, a promotional video for the second cours starting on July 23 was released. Eir Aoi performed the new ending theme song "HELLO HELLO HELLO".[69]
A second season was announced in July 2024. It is set to premiere in 2025.[70]
"You're going to be my boyfriend." Transliteration: "Watashi no Kareshi ni Narinasai yo" (Japanese: 私の彼氏になりなさいよ)
Yoshiyuki Shirahata
Yasuhiro Nakanishi
Yoshiyuki Shirahata
April 24, 2022 (2022-04-24)
Sixteen years ago, two babies are accidentally switched at birth. In the present, Nagi Umino is to meet his biological parents for the first time. Nagi sees a girl, Erika Amano, about to jump from a bridge and pulls her back. She explains she was recording a video for Inusta, on which she is an internet celebrity, to antagonize her wealthy parents into letting her out of an arranged marriage. She instead blackmails Nagi into pretending to be her boyfriend. Several of Erika's fans attempt to beat Nagi for dating Erika, but Nagi beats them instead, revealing his adoptive parents are former delinquents. Erika decides to simply punch her fiancé instead of blackmailing Nagi and departs. Nagi rushes to the meeting with his adoptive and biological parents who explain that since they don't want to lose the children they raised, they instead want them to marry. Erika walks in and is revealed as the baby with whom Nagi was switched, now his official fiancé. Erika follows through on her decision and punches him. Nagi returns to school and sees Hiro Segawa, his academic rival and crush whom he has decided to only confess to once he has beaten her exam scores as she once told him she would only date a man smarter than herself. Meanwhile, Nagi's sister, Sachi, realizes the revelation means they aren't blood-related siblings.
2
"I'm not going to marry you." Transliteration: "Kekkon nara Shinai wa yo?" (Japanese: 結婚ならしないわよ？)
Nagi is surprised when Erika visits his home. Due to her wealthy upbringing, Erika is completely out of touch with normal life and struggles to believe Nagi's entire family lives in such a small house. She invites Nagi to her family home, an opulent mansion, also revealing they own six similar homes throughout Japan and other countries. Nagi begins to have serious doubts a marriage between them would work and decides he needs to reject their engagement. Erika suddenly rejects him first and demands to see his parents and tell them so. At their diner, Nagi's parents fawn over Erika, and Nagi panics while Erika visibly becomes more upset. When they insist Erika meet Sachi, her biological sister, Erika abruptly leaves crying, revealing to Nagi his parents are such kind people she couldn't stand to disappoint them by ending the engagement. After reassuring her, Nagi brings her back to the diner and everyone has a family dinner together. Sachi covertly adds Erika's chopsticks to their family utensil jug, suggesting she likes Erika. Walking Erika home, Nagi meets her father, his biological father, who is confident that despite their unusual meeting, they will do well as a married couple, so confident in the fact that to prove it he has bought them a house and insists they live there together for two weeks.
3
"You aren't going to beat me!!!!" Transliteration: "Zettai ni Makenai kara!!!!" (Japanese: 絶対に負けないから!!!!)
Yoshitaka Nagaoka
Yasuhiro Nakanishi
Yoshitaka Nagaoka
May 8, 2022 (2022-05-08)
Nagi decides to spend the two weeks studying for his next exam to defeat Hiro. He hears Erika scream and barges into the bathroom, finding her completely naked, having been startled by a harmless lizard. Nagi is forced to borrow Erika's study materials in exchange for taking pictures for her social media. By accident, they take several pictures that make them look like a couple. Nagi explains he is obsessed with studying so he can support his parents when they retire, whereas Erika likes social media because she hopes if she becomes famous someone she has been looking for will contact her. Nagi discovers he has actually defeated Hiro in the exam and Hiro asks to meet him alone. Nagi expects her to confess now he has proven he is smart enough for her, but instead she declares she only lost because she missed the exam due to a family funeral, and she will beat him on the next exam. Her competitiveness makes Nagi admire her even more. Nagi catches a cold and passes out still trying to study. Erika looks after him and admits his devotion to studying impressed her, surprising Nagi as everyone else keeps telling him he studies too much. Hiro is shown to be pushing herself even harder so she can defeat Nagi.
4
"Would you please go out with me...?" Transliteration: "Ore to Tsukiatte Kuremasu ka...?" (Japanese: 俺と付き合ってくれますか…？)
Shūji Saitō
Yasuhiro Nakanishi
Hiroki Itai
May 15, 2022 (2022-05-15)
Hiro asks Nagi why he tried so hard to beat her, so explains how he knew she would only date someone smarter than her. Hiro reminds him this was only the first exam he has beaten her in, whereas she has beaten him in ten; she also reveals she is already engaged. Erika reminds Nagi it is his last night living with her and they agree to tell their parents they hated the experience. However, Nagi learns his family moved into a hotel after a pipe burst at their home, forcing him to continue living with Erika. Sachi is upset Nagi won't be coming home and decides to visit. Erika panics as Sachi is technically her real sister. The initial meeting is awkward so to break the ice, Nagi insists they cook dinner together. Erika has never cooked and is ignorant of the basics, whereas Sachi is unfamiliar with the expensive gadgets in Erika's kitchen, so Nagi ends up doing most of the cooking. During dinner, he points out that Erika and Sachi are actually quite alike in their behaviors. Erika gives Sachi some of her dresses after learning she only owns her school uniform and Nagi's hand-me-down boy's clothes. She also lets Sachi know she and Nagi have no intention of going through with the marriage. Before she leaves, Sachi takes a picture with Erika.
5
"Can we do our morning study sessions together...?" Transliteration: "Issho ni Asa Katsu Dekiru ka na...?" (Japanese: 一緒に朝活できるかな…？)
Chihiro Kumano
Yasuhiro Nakanishi
Hiroaki Yoshikawa
May 22, 2022 (2022-05-22)
Nagi tries to avoid Hiro but is surprised when Hiro approaches him asking to study together, giving him hope she prefers him to her fiancé. They realize they both collect commemorative Shinto shrine stamps, so they compete over collecting the most stamps. Hiro asks if they can study together every morning and Nagi considers telling her he is engaged. Erika transfers into his class, explaining she accidentally uploaded one of their fake couple pictures to the internet. Her all-girls school demanded she attend a disciplinary meeting but she skipped it due to caring for Nagi during his cold, so her father transferred her to Nagi's school. She forbids Nagi from telling anyone at school they are engaged. As a class rep, Hiro shows Erika the school and Nagi is terrified of what might happen if his fiancé and his crush become friends. He eventually decides Erika needs a real friend, unlike the shallow girls at her previous school, and helps her, for which Erika is grateful. Hiro is suspicious at how Nagi knows so much about Erika so she claims he is a fan, causing another bout of competitiveness between them, as Hiro turns out to be a big fan of Erika. Hiro invites Erika to attend her and Nagi's study sessions, making Nagi feel even more awkward.
6
"I thought you lived by yourself." Transliteration: "Hitori de Sunderun da yo ne?" (Japanese: 一人で住んでるんだよね？)
Yoshiyuki Shirahata
Yasuhiro Nakanishi
Yoshiyuki Shirahata
May 29, 2022 (2022-05-29)
Nagi admits to Erika that he confessed to Hiro, so she decides to help him. At their first study session, Erika literally dresses as Cupid, but her efforts fail. The way they argue makes Hiro suspicious due to how close they act. Hiro asks if she can visit Erika's home to study. Nagi tells Erika to take Hiro to her original mansion, only for Erika and Hiro to arrive at their house as her mansion is being remodeled. Communicating through text, Nagi hides all the evidence of them living together before hiding in his room. Unfortunately, the obsessive fans Nagi beat up when he first met Erika find the house and break into the garden, forcing Nagi to leave his room to beat them up again. Hiro finally leaves and the next day invites them to her home to study, revealing her family manages the local shrine where Nagi is able to collect their shrine stamp. They meet Hiro's mother, who is less than happy at Nagi's presence. While Erika is away Hiro admits that when she said she was engaged she actually meant that one day she would inherit the shrine, but phrased it to sound like she had a fiancé to deter Nagi from pursuing her. She suspected he would probably give up his future plans to run the shrine with her and didn't want to place that burden on him.
7
"Is my fate going to change?" Transliteration: "Unmei, Kawatchau no ka na?" (Japanese: 運命、変わっちゃうのかな？)
Marina Maki
Yasuhiro Nakanishi
Yoshiaki Okumura
June 5, 2022 (2022-06-05)
Privately, Nagi decides he can run the shrine and must learn more about Hiro's family. A field trip to Kamakura approaches and while Erika refuses to go, she manipulates Nagi into going by helping him form a group with Hiro. Hiro insists their group project be a contest to collect the most shrine stamps. When asked about her answer to his confession, Hiro admits her parents are forcing her to inherit the shrine, which she does not want, and wants Nagi to change her fate. Erika reveals one of her fans from the class named Shion has forced his way into Nagi's group, having mistakenly assumed Erika would be in the group, so she agrees to go to prevent him from bothering Nagi and Hiro. Shion turns out to be an annoying superfan but does help Erika take excellent photos. Nagi watches them constantly, so much so he forgets to spend time with Hiro who goes stamp collecting alone. Nagi decides to help Erika take another photo but they argue over it so much they accidentally take another perfect couple photo, though it ends up being Erika's favorite. Nagi asks about the mystery person Erika has been searching for and she warns him knowing who the person is would change his future.
8
"Are you going to marry him?" Transliteration: "Kono Mama Kekkon Shichau no?" (Japanese: このまま結婚しちゃうの？)
Yoshitaka Nagaoka
Yasuhiro Nakanishi
Yoshitaka Nagaoka
June 12, 2022 (2022-06-12)
The next day, Erika runs errands and while she is away, Sachi visits. Based on his attitude she accuses Nagi of fighting with Erika until he admits his dilemma and decides he will ask Erika who she is looking for. Sachi decides to live with Nagi and Erika, claiming the rented room she shares with their parents makes studying difficult. Nagi attempts to be strict with her but gets no support from Erika who is glad to see Sachi. Once alone, Erika asks Sachi's real motive and Sachi admits since Erika appeared she has been scared she and Nagi will marry and she will never see him again. Overhearing this, Nagi decides to let her stay but immediately regrets it as Sachi takes his room. Forced to go shopping for Sachi's essentials, Nagi realizes Sachi is popular with people. Erika insists on taking new family photographs including Sachi and moves her into her bedroom, learning Sachi talks in her sleep. Nagi finally talks to Erika and admits that he is not yet ready for his future to change, but once he is he would like to know who she is searching for. Erika is amused that he has been worrying but agrees to tell him once he is ready.
9
"The Kuroshio currents beckon to me." Transliteration: "Kuroshio ga Ore o Yondeiru ze...!!" (Japanese: 黒潮が俺を呼んでいるぜ…!!)
Hiro asks Nagi on a date to an amusement park but he is disappointed when she admits she needs him for the two-person discount. She apologizes for having left him during the trip to Kamakura as she had gotten lost. While exploring a mirror maze, Nagi believes he accidentally kissed Hiro, which amuses her as he had actually kissed a mirror. Sachi is in a foul mood she claims is caused by Nagi being on a date, despite being Erika's fiancé. She takes Erika to a baseball center and then to a public bath where Erika admits she is glad Sachi is her sister, but Sachi is still upset everything is changing. Returning from his date, Sachi makes sure to torment Nagi over it; meanwhile, Erika decides to invite her mother to the bathhouse. In the middle of the night, Nagi and Sachi's father, Yohei, appears to take them all fishing, something Nagi despises due to seasickness, as he wants to spend time with all his children. Remembering that Yohei said he would stop taking him fishing if he caught a bigger fish than him, Nagi becomes super serious about fishing but still only catches the smallest fish. By the end of the trip, Nagi realizes Yohei only ever dragged him fishing when he was stressed, helping Nagi take his mind off the problem, so he thanks Yohei for his help. Erika wonders what kind of person she might have become had she been raised by her biological family.
10
"Don't treat me like your kid sister." Transliteration: "Imōto Atsukai Shinaide yo" (Japanese: 妹扱いしないでよ)
Chihiro Kumano
Yasuhiro Nakanishi
Ken'ichi Nishida
June 26, 2022 (2022-06-26)
Erika spends Mother's Day with her mother, Ritsuko. Sachi decides to get their mother, Namie, a gift and seeks Nagi's help. Eventually, they decide on an apron she can wear in the restaurant. Nagi pats Sachi's head for thinking of the idea, which annoys her that he is treating her like a little sister. They deliver the apron but leave without being seen. Erika tells Ritsuko she sometimes thinks Nagi might be better off marrying Sachi. The next day, Erika receives a text from her father, Soichiro, and immediately drags Nagi out shopping, eventually revealing Soichiro asked to visit so she is avoiding him in case he wants to take her home. Soichiro arrives and finds only Sachi, so he takes her to dinner in exchange for telling him about Erika and Nagi. Erika decides to confront Soichiro but Nagi instead chooses to help her continue avoiding him. Sachi admits that, even though Erika and Nagi argue constantly, they are closer friends because of it. Soichiro offers to continue bribing Sachi with sweets in exchange for updates on Erika and Nagi, which Sachi accepts. Soichiro returns to his office where he ponders the child rearing practices of cuckoo birds and reveals a picture of himself, Ritsuko, Erika, and a boy that looks like Nagi.
11
"I can't forget that just happened." Transliteration: "Nakatta Koto ni Nante Dekinai yo" (Japanese: 無かったことになんて出来ないよ)
Shūji Saitō
Yasuhiro Nakanishi
Jun Hatori
July 3, 2022 (2022-07-03)
Sachi returns to working at their parents' diner but still refuses to move back home. Lightning knocks out the city's power, leaving Nagi and Erika in the dark. Erika asks if Nagi enjoys living with her since she has enjoyed every day since meeting Nagi and Sachi. Nagi admits he has enjoyed himself too. In the dark Nagi bumps into and kisses Erika, only for the lights to come back on and reveal he actually kissed Sachi who had just gotten home. Sachi is embarrassed but becomes angry when Nagi points out he thought she was Erika and should just forget the kiss. The next day Sachi treats Nagi coldly but when her friends at school discuss a TV show that includes siblings falling in love she starts to wonder if she loves Nagi. Erika notices the tense atmosphere and, when Nagi explains about the accidental kiss, points out just how much he screwed up. He might consider Sachi his little sister, but Sachi is almost a grown woman and not even his blood relative. Nagi is unsure how to apologize, but after a pep talk from Hiro he manages to apologize to Sachi and promises to stop thinking of her as a child but as a woman. Sachi forgives him and begins acting much happier.
12
"It's not that I like you, yet." Transliteration: "Suki ja Nai, Mada" (Japanese: 好きじゃない、まだ)
Mayu Numayama
Yasuhiro Nakanishi
Kunihisa Sugishima
July 10, 2022 (2022-07-10)
Erika asks Nagi to take her shopping but he refuses, claiming he has plans. He invites Hiro to study to make up for embarrassing himself at the amusement park. As the public library has a no-talking policy they are forced to communicate through notes, though this ends up being more intimate. Hiro invites Nagi to a kickboxing gym. Erika sees them sparring and becomes upset. The next day Erika demands Nagi take her on a date. After forcing him to go jogging she explains she thought he enjoyed exercise since he went kickboxing. Since Erika has never experienced jealousy before, Nagi has to explain that jealousy means she must like him. This infuriates her so she blurts out she doesn't like him “yet”, then runs away. The “yet” confuses Nagi and he starts to wonder if maybe he likes Erika. He visits his parent's restaurant where by chance he discovers embarrassing love letters Yohei wrote to Namie in high school. Yohei claims love causes people to do embarrassing things, but if it is true love it is worth it. Nagi doubts he could do it so Yohei demands he just feel who is in his heart. Nagi does so and becomes even more confused when he feels Erika, Hiro, and Sachi all have equal places in his heart. Erika later receives a text from Nagi stating he also doesn't like her “yet”.
13
"Things aren't quite working out, are they?" Transliteration: "Nakanaka Umaku Ikanai nē" (Japanese: なかなかうまくいかないねぇ)
Yoshitaka Nagaoka
Yasuhiro Nakanishi
Yoshiaki Okumura
July 24, 2022 (2022-07-24)
Nagi is so distracted by his feelings during exams that not only does Hiro retake first place, he falls to 13th in the exam rankings. Hiro appears upset by this, which makes Nagi feel worse. Erika doesn't see the problem until Sachi reminds her Nagi has never once fallen below 2nd place, let alone 13th. Nagi blames his overconfidence on having beaten Hiro once, plus barely studying since he started having fun with Erika. Erika manages to argue him into feeling better. The next day Hiro is unexpectedly late to their morning study session, but when she does arrive and hears Nagi and Erika arguing like usual, she decides to leave and becomes even more distant from Nagi. Nagi is depressed until he receives a sudden summons from Hiro to meet her. Erika is convinced Hiro has given up on Nagi after his disastrous exam results and is probably going to permanently reject him. However, Hiro is unconcerned with his grades and is more upset that it was Erika who made him feel better, and not her, his academic rival. Realizing he still loves Hiro and she still cares for him Nagi begins studying properly again. Erika asks for his help to fix her own terrible grades, revealing if she fails any of her next exams her parents will force her to move back home with them.
14
"Walls exist to be overcome!!" Transliteration: "Kabe wa Koeru Tame ni Aru!!" (Japanese: 壁は超えるためにある!!)
When over three hours she can't answer a single question Erika resigns herself to moving out. Nagi is disappointed as he and Sachi will have to move back home to their parent's cramped flat. Later he realises Erika has been studying by herself all night and Sachi demands that, rather than half-heartedly teaching while doing his own studying, he should teach her properly. Realizing he hasn't been of any actual help Nagi bursts into Erika's room and announces he will teach her the most basic technique to pass exams, rote memorization of typical exam questions. After a weekend of intense study, Erika gets a passing grade. Soichiro is happy his plan to manipulate Erika worked. Sachi invites Erika to a festival near their parents' diner, though she and Nagi are expected to help run their parent's yakisoba stall. Sachi is intensely embarrassed when a customer thinks she and Nagi are a couple. Hiro appears and asks Nagi to visit the rest of the festival once he is done working. Sachi is irritated he won't be going with her and Erika. Later, Hiro meets Erika and Sachi together but is confused about how Sachi is somehow both Erika and Nagi's sister.
15
"We have to tell her... about our secret!" Transliteration: "Iu Shikanai, Oretachi no Himitsu...!" (Japanese: 言うしかない、俺たちの秘密…！)
Nagi and Erika end up alone at the festival. Erika draws attention from her fans, so Nagi buys a mask. Nagi bumps into Sachi with her friends and overhears them teasing Sachi about her brother-complex. Erika is suddenly swarmed by the fans who tried to break into their house, one of whom has trained his muscles for his rematch with Nagi. Not wanting to cause a scene Nagi and Erika flee. Erika decides this summer has been her favorite, even compared to summers she spent with her parents on foreign holidays. They watch the fireworks together, and both Sachi and Hiro are disappointed they didn't get to watch them with Nagi. Hiro catches up to them and finally asks how they are related since they both claim Sachi is their sister. Nagi feels guilty so they finally tell Hiro about being switched at birth and now engaged. Hiro accepts the explanation and Erika hopes they will now be better friends. As she has to buy a gift for Sachi Erika remains at the festival while Nagi walks Hiro home. Hiro makes Nagi promise to never keep another secret and he agrees, though their interaction is seen by Sachi. Nagi returns home happier than ever while Sachi asks Erika about Hiro.
16
"I want to talk about now." Transliteration: "Ima no Kaiwa ga Shitain Desu" (Japanese: 今の会話がしたいんです)
Erika and Sachi spend all day following Hiro but find nothing suspicious about her. Sachi announces she plans to attend the same high school as Nagi and begins studying diligently. Nagi shares with Erika how he feels Sachi is acting strangely and feels less and less like a sister. Sachi attends an open-day at the school with Hiro as her guide. Sachi asks Hiro what she thinks about Nagi. Hiro repeats her claim she is engaged but admits she is fascinated by Nagi. Nagi rushes to hear what they are saying but finds Sachi and Hiro have somehow become friends. At home, Sachi has kept on studying but Nagi remains worried as their school is a private academy with yearly fees and their parents already struggle to pay just for him. However, their parents decide if Sachi gets accepted they will just sell their restaurant to pay the fees. Sachi refuses to let that happen and a battle of wills breaks out between Sachi and Namie with Nagi and Yohei terrified and powerless to stop them until Erika steps in to calm everyone. As they return home Sachi calls Erika Sister for the first time, leaving Nagi disappointed she didn't call him Brother.
17
"Anything could happen right now!" Transliteration: "Nani ga Okite mo Okashikunai node wa!!?" (Japanese: なにが起きてもおかしくないのでは!!?)
Nagi, Erika, and Hiro decide to study at Erika's holiday home in Karuizawa, though Shion invites himself as well. Erika makes sure to hide a photo on a display table before anyone sees it. Shion goes food shopping with Erika, leaving Nagi alone with Hiro. Hiro decides they should sneak away to a nearby lake where she admits sometimes she finds it hard to focus on studying. Shion decides there is something he wants Erika to know. Hiro decides to take a bath, distracting Nagi who cannot study knowing Hiro is naked. Erika returns and joins Hiro in the bath. Shion claims he confessed to Erika, though it transpires he only thanked her for inviting him to study with them. Nagi is relieved it wasn't a confession but then confused as to why he was relieved. Erika reveals to Hiro she forgot to pack anything for the trip, like underwear or pajamas. They attempt to study until Shion reveals he found a shrine in the forest perfect for a test of courage. Shion plans to go with Erika and Nagi with Hiro, but Erika suddenly chooses to go with Nagi, claiming she has something important to discuss. Knowing Nagi needs to beat Hiro at exams to date Shion asks why Hiro is obsessed with scoring the highest. She avoids answering and instead offers to help Shion confess to Erika, though she hides her reason for doing so.
18
"Who is that person?" Transliteration: "Sono Hito wa Dare...?" (Japanese: その人は誰…？)
Shūji Saitō
Yasuhiro Nakanishi
Ken'ichi Nishida
August 28, 2022 (2022-08-28)
Sachi, sick with a fever, is taken to hospital. Erika explains to Nagi she has run out of underwear and is naked under her dress, so she brings him with her as he is the only one she trusts to walk her to a convenience store to buy some. After dinner, Hiro comments Nagi seems happier and he realizes he is actually enjoying himself. Nagi suggests they go star-gazing but he receives a text from Namie about Sachi. Erika eventually realizes Nagi is missing, having left to get the train home without telling anyone. At the hospital, Sachi scolds Nagi for abandoning his friends but is happy he came. Erika returns home and Nagi is surprised she agrees he did the right thing. Her response makes Nagi realize due to their different upbringings he really has no idea about Erika's personal life. Hiro ponders a picture she saw, the one Erika tried to hide. Soichiro goes to Karuizawa and retrieves the picture, revealing it is the picture showing Erika and a boy resembling Nagi, and that he placed it there hoping Nagi would see it. Nagi confronts Erika about the person she is trying to find, having realized it must be someone she loves, and finally asks her who it is, regardless of the consequences.
19
"You must have noticed by now." Transliteration: "Mō Kizuite Irunda yo ne...?" (Japanese: もう気づいているんだよね…？)
Shinya Sasaki
Yasuhiro Nakanishi
Kunihisa Sugishima
September 4, 2022 (2022-09-04)
Erika shows Nagi the picture and confirms that it is not actually Nagi, it is her older brother Sosuke, Nagi's biological older brother. She is surprised when Nagi fails to react to the news. For unexplained reasons, Erika's parents pretend Sosuke does not exist, but Erika always wanted to see him again and when she first met Nagi she initially thought he was Sosuke. Erika is close to giving up being an internet celebrity as her fame has not prompted Sosuke to contact her even once. Nagi decides they will find Sosuke together by searching for him directly instead of waiting for him to contact Erika. Sachi finally returns from the hospital. Nagi thinks back over his every interaction with Erika and convinces himself he was just a substitute for Sosuke. He decides to ask his biological parents, Soichiro and Ritsuko, the truth about Sosuke. Soichiro turns out to have been expecting Nagi to visit. Erika tells Sachi about Sosuke and Sachi realizes it explains a lot about Erika's personality; she is a younger sister too. Soichiro continues to claim Sosuke does not exist and shocks Nagi by suggesting that all his troubles would be solved if Nagi married Sachi.
20
"I want to grow up already!" Transliteration: "Hayaku Otona ni Naritāi!!!!" (Japanese: 早く大人になりたーい!!!!)
Fumio Maezono
Yasuhiro Nakanishi
Yoshiaki Okumura
September 11, 2022 (2022-09-11)
Nagi returns home frustrated at having learned nothing about Sosuke and finds Erika and Sachi preparing for summer break. Erika is unsurprised he failed and surprisingly does agree Nagi could technically marry Sachi, but then goes quiet when Nagi points out, by Souichiro's logic, Erika could marry Sosuke. Out of nowhere, Hiro invites Nagi on a second date to go bicycling. Before they leave she poses him a riddle; What is the nearest and farthest thing? On their ride, Nagi thinks about Souichiro's confusing and irritating behavior. He and Hiro arrive at a beach where Hiro reveals the riddle answer is Family. Nagi admits he is frustrated by Souichiro while Hiro admits she wants to grow to an adult as quickly as possible, but doesn't explain why. Sachi has another meal with Souichiro who outright asks her if she is willing to marry Nagi. Returning home Sachi begins acting distantly, worrying Nagi with her behaviour. Sachi becomes angrier every time Nagi acts like an older brother and, in her frustration, asks him if she were to propose marriage to him would he marry her? When he claims he wouldn't because she is his sister, she pretends to have been joking.
21
"It's a secret between you and me." Transliteration: "Watashi to Nagi-kun dake no Himitsu jan" (Japanese: 私と凪くんだけの秘密じゃん)
Takatoshi Suzuki
Yasuhiro Nakanishi
Ken'ichi Nishida
September 18, 2022 (2022-09-18)
Nagi receives his end-of-year report and, despite his temporary fall to 13th place, has risen to 1st. Nagi hopes he and Hiro will start dating, but Hiro turns him down again, citing the existence of her fiancé, though she does wish she were Nagi's fiancé instead. Erika invites everyone to one of her beach houses so they can discover what Hiro means. Erika decides Hiro can't discover they are living together, but when they return home Sachi invites Hiro over to study. Hiro is actually not surprised as she had suspected they lived together for some time. At the beach, Nagi asks why Sachi told Hiro the truth. Sachi claims it was so Hiro could come over more often to tutor her, so Nagi shouldn't complain as it means he can see Hiro more often. Nagi is unsure so Erika offers to talk to Hiro since she suspects Souichiro is really to blame. Nagi apologizes to Hiro, and while she isn't upset he has been lying, she does seem upset that he has fun with Erika while living together. She forgives him and then reveals Sachi has a crush on him, to his disbelief. Erika is convinced Hiro is in love with Nagi but Sachi is doubtful. Nagi bluntly asks Sachi if she has a crush on him, and though she punishes him for embarrassing her, she never actually denies it.
22
"I'll be with you when you meet him." Transliteration: "Au Toki wa Ore mo Issho da" (Japanese: 会う時は俺も一緒だ)
Yoshiaki Okumura
Yasuhiro Nakanishi
Kunihisa Sugishima
September 25, 2022 (2022-09-25)
Sachi is mad at Hiro for what she told Nagi but is also confused about what Soichiro had said. Nagi decides to bathe naked in Erika's outdoor bath and is shocked when she joins him, also naked. At first Nagi thinks she is trying to seduce him, realising too late Erika actually had a bikini on. Later, Erika explains the house only has two beds and by drawing lots Sachi must share with Nagi. Erika asks about Hiro's fiancé and she admits she has never met him. Hiro then asks if Erika would let her marry Nagi instead, but Hiro falls asleep before Erika can answer. Nagi cannot sleep so close to Sachi so he leaves and finds Erika, who had remembered she and Sosuke came to the beach house every summer. From this, Erika finds evidence on a games console that Sosuke was in the beach house only three days ago. Hoping Sosuke might still be in the nearby town Nagi rushes to locate him. Erika is scared that they might find Sosuke so suddenly after years of searching and can't think what she would say to him, so Nagi promises to support her. After searching all day no one in the town knows Sosuke, so Erika decides Sosuke must have left already, but is still grateful to Nagi for his help.
23
"What should we do now?" Transliteration: "Kore kara Dō Shiyokka" (Japanese: これからどうしよっか)
Hiro announces she and Nagi will travel home separately from Erika and Sachi and take the train to a nearby shrine so they can collect the stamp together. Erika reveals to Sachi that Hiro wants to marry Nagi. The train is cancelled, stranding Nagi and Hiro. Erika and Sachi are horrified when Nagi texts them that he and Hiro will be staying the night. Nagi is embarrassed when, in order to get a hotel room, he and Hiro must claim to be married. Nagi promises to sleep on the floor but when Hiro trips over her bath robe they end up on the bed. Nagi tries to stand but Hiro comments that, since they lied to get the room, doing another bad thing won't matter. Nagi is embarrassed when Hiro actually suggests they buy alcohol as she is tired of being a perfect student and wants to misbehave for once. The police suddenly arrive and Nagi panics as he worries lying about their age will lead to being expelled from school. It turns out to be a prank by Erika and Sachi who hired a taxi to pick them up. As Nagi was half naked and changing clothes, he is punished by Erika and Sachi who demand to know if anything happened but Hiro gives a deliberately vague answer as they drive home.
24
"All that matters is that you two are happy" Transliteration: "Futari ga Shiawase nara Sore ga Ichiban jan" (Japanese: 二人が幸せならそれが一番じゃん)
Nagi, Sachi and Erika are invited to Yohei's birthday. Erika looks at photos from Yohei's previous birthdays and sees in one of them a young girl with silver hair. Namie and Yohei reveal they wanted Nagi and Erika to marry as a way to keep all their children together, but they no longer worry about it. Nagi and Erika realise that there really is no longer a reason for them to stay engaged. The next day Erika comes down with a fever. Sachi and Hiro appoint themselves her nurses but Erika sends them away. Nagi steps in and discovers Erika has been so concerned about Sachi and Hiro she tired herself out until she became sick. Erika asks how Nagi knows her so well and he claims it is because she is his fiancée. Overhearing, Sachi and Hiro realise Erika will always be closest to Nagi, upsetting Hiro in particular. Yohei sends them a copy of his birthday photo, which includes Erika. Erika wonders if one day she will have a family like Nagi's, and Nagi hints anything is possible. Sachi sneaks out to another meeting with Soichiro who is pleased Nagi and Erika are making good progress towards marriage but he intends it to be their choice without pressure from him. Meanwhile, Erika and Nagi resume arguing about household chores and both despair about being engaged to someone so irritating.
Reception
It was reported that the first volume of the manga sold out in stores due to high demand, and that sales exceeded the publisher and author's expectations.[73]A Couple of Cuckoos ranked twelfth on Takarajimasha's Kono Manga ga Sugoi! list of best manga of 2021 for male readers.[74] The series ranked fifth on the "Nationwide Bookstore Employees' Recommended Comics of 2021" by the Honya Club website.[75][76] The manga has been nominated for the 46th Kodansha Manga Award in the shōnen category in 2022.[77]
