Live and Learn (1971)

Original title: すっぽん女番長

Tetsuko (Eiko Yanami), a high school student, one day, forces Tsuneo, (Kei Wakakura), the brightest boy in her school, to make love to her after school is out and they are caught by the old school janitor. Tsuneo's mother, orders Tetsuko to pay for what she did to her son but Tetsuko blackmails her instead, saying that she is ready to inform a news company of what has happened to Tsuneo and receives one million yen hush money. Expelled from school, she comes to Tokyo, intending to take a round-the-world trip. But Sankichi (Yoshihiko Aoyama), a jack-of-all-trades, cheats her. So, she makes up her mind to catch him and get back her money.