Yoshirou Takagi, a recluse young adult (hikikomori), adopts a stray cat, Kiki, which magically turns into a catgirl, i.e. a human girl with feline characteristics, who attempts to help him deal with his solitude.
Catgirls are common themes in otaku media. As Yoshirou teaches Kiki how to behave more like a human, he also makes her wear a maid cosplay and a Japanese school uniform, which are other references to the Akihabara cosplay culture.