Shinryaku RPG

A completely normal day goes completely insane when video game monsters being to storm Tohru's high school. Forced into the role of hero, Tohru is powerless to prevent his friends and classmates from being transformed into robotic NPCs. He's not the only one left with free will, and perhaps he and his friends can make a difference. That is, if the students who find themselves to be villains don't stop him.

(Source: Mangamo)