My Friend Turned into My Favorite Dating Sim and Came on to Me

Sota Yomoyama is an inexperienced university student who claims to like girls, even though he is into yaoi manga and has a crush on a (male) love interest in a dating sim game. The only male friend who tolerates his interest in these things is his best friend, Tatsuhiko Miki.
Sota is comfortable enough with Tatsuhiko to gush to him about his favorite character, Klaus. As soon as Sota says he wouldn't mind being embraced by Klaus, Tatsuhiko pins him to the wall and wraps his arms around him...!
As if that weren't enough, Tatsuhiko gets a makeover to look like Klaus and comes after Sota tenaciously...! Pinned to the wall, carried over the threshold, and taking it further in the nurse's office...! Oh, no... if this goes on, they'll get a mature rating...!!