Okane ga Nai! [OVA]
Yukiya Ayase is a regular university student with no job. His cousin Tetsuo Ishii betrays and sells him in an auction to settle his heavy debts. Ayase is bought by Somuku Kanou for 120 million yen.
Kanou does this because he remembers Ayase from 4 years ago, when Ayase, a stranger, helped him. Now Kanou wants to keep Ayase close to himself, and uses the debt of 120 million yen to force Ayase to live with him. As Ayase is still a student and does not have a job, he is forced to sell his body to Kanou for 500,000 yen each time they have sex.