On March 30, 1935, the initial 8.7 km section of the Itō Line linking Atami with Ajiro was opened. The second (8.3 km) section from Ajiro to Itō was opened on December 15, 1938. Both sections were electrified at 1500 VDC when opened. Further work was delayed, and then canceled due to the outbreak of World War II.
Construction south of Itō resumed when the private-sector Tokyu Corporation acquired the rights to complete the line to Shimoda and established the Izukyū Corporation to manage construction and operations of this section. The line to Shimoda opened in 1961.
Operation
The northern terminal station for the Izu Kyūkō Line is at Ito Station, from which local trains depart for the southern terminal station of Izukyū-Shimoda. However, several varieties of limited express trains operated by JR East originate at Tokyo Station travel via the Itō Line tracks to Ito, and then terminate at Izukyū-Shimoda. These include the Odoriko and Super View Odoriko named trains. Similarly, the Resort Odoriko operated by the Izu Kyūkō Line also makes the same run, but using different rolling stock.
