Change Drug

Amane, a broke college student, decides to participate in a clinical trial for a new drug. He encounters a suspicious-looking doctor passed out on the floor the moment he steps into the institute. The doctor introduces himself as Mishima and, for some reason, takes a liking to Amane... The trial begins, and suddenly Amane is passed out on the floor. When he comes to, Amane realizes that his chest is a little bigger... and something is missing that he used to have! This new body is too much for Amane to handle, and Mishima is all too happy to help "take care of" Amane's new condition.

(Source: Renta!)