The Kama-Kama Line (蒲蒲線, Kama-kama sen) is a proposed 3.1 km railway line in the city of Ota, Tokyo, Japan, connecting the Tōkyū Tamagawa Line (which currently terminates at Kamata Station) to the Keikyū Airport Line (which currently terminates at Keikyū Kamata Station).
Due to differences in track gauge, the Kama-Kama Line would not offer through service to Tokyu, but a new underground transfer platform would be built at Kamata Station to facilitate transfers between Tokyu and the new line. (However, Ota City's plan calls for Gauge Change Train through service to the Tokyo Metro Fukutoshin Line.) On the other end, it would offer through service to Haneda Airport through the existing Keikyu Airport Line and would stop at a new underground platform at Keikyu Kamata. One envisioned purpose of the line is to carry Haneda traffic to and from central Tokyo stations such as Ikebukuro and Shibuya via the Tokyu network.
The line is estimated to cost around 108 billion yen. Although the Tokyo metropolitan government has indicated skepticism about the need for the line, Ota has promoted its construction to national government officials. A study released by Ota in December 2015 estimated the economic impact of the line at around 239 billion yen, of which construction impact would account for around 184 billion yen and passenger consumption impact would account for around 54 billion yen.