JUNJOU SHOUNEN

Junjou Shounen summary:

Kusaka Taisei was born into a good family without knowing much about the world. He became interested in the reserved and tranquil beauty of the transfer student, Mizutani Aoi. On a day off from school, Kusaka spotted Mizutani going somewhere, and gave into his urge to trail behind him.
Kusaka arrived to see a sex parlor in front of him. It was inside there that he encountered Mizutani and was invited into a private room. In exchange for keeping quiet, Kusaka was given a blow job.