Itsumo Dareka ni Koishiteru (1990)

Itsumo Dareka ni Koishiteru 1990 / いつも誰かに恋してるッ 1990 / Always in Love with Someone , いつもだれかにこいしてるっ

While vacationing in Okinawa, teenager Satoko is rescued from drowning by the handsome Kizuku. He becomes a fantasy figure for her, like a modern-day knight in shining armor, though that all changes when he transfers to her school. The idealized holiday romance soon sours when Satoko discovers more about Kizuku's true nature, and that while he may base saved her life, he is a juvenile delinquent. (Source: DramaWiki)