Bekkan 3-kai Danshi Toilet no Nikubenki

At the boys' school the protagonist attends, a persistent rumor claims that girls will have sexual encounters with students in the restrooms on the third floor of the annex. His friends laugh off the idea, telling him the annex is nothing more than a hangout for delinquents. Even so, he cannot let the rumor go. Hoping to learn the truth for himself, he decides to visit the annex despite their warnings. What he finds there matches his friends' description all too closely. The annex has indeed become a gathering place for delinquents, and before he can investigate further, they discover him. The confrontation immediately turns threatening when they order him to hand over his wallet. Just as the situation seems to be heading toward a routine robbery, however, the delinquents say something completely unexpected, leaving the protagonist caught off guard.