The protagonist is in the middle of preparing for a presentation at a college seminar.

Ryousuke Kamiya, a college student, was browsing porn videos while taking a break when he stumbles upon a video featuring Yuuka Someya, a girl attending the same seminar! When he asks her about the video at a drinking party after the presentation, he finds himself being offered sex in exchange for not telling anybody about it...?!

(Source: DLsite)

Published in Comic Ananga Ranga.

[Note: This has 2 near-identical versions, one is a fully censored softcore version and the hardcore version marked R-18 has black bars. The covers are slightly different, but the story is the same.]

Additional Links:

• DLsite