From Renta:

High-schooler and gamer Taiga is in love with the character Miori, a promiscuous girl from a dating sim. One day, Taiga loses track of time and heads home late from school. As he passes by the supposedly-closed boy's restroom, he hears moaning and peeks inside... Only to find honor student Hibari getting rammed and crying out in pleasure...!! The next day, Hibari reveals to Taiga that he knew of his sneaky, peeping-tom ways and drags Taiga into the restroom...! A thrilling love story between a geeky boy and a secretly seductive honor student!!