Ohime-sama ni Narenakatta Boku wa Kyou mo Gakuran ni Sode o Tousu

Inaba Tomoyo's life was plain and ordinary, until one day, in an empty classroom after school, a girl asked him out for the first time ever. But what happened next was even more surprising. After she left, Mizukoshi Tatsurou, a classmate of Inaba's came in. He seemed to have heard the two talking. Inaba thought he would make fun of the whole thing, but Mizukoshi seemed angry...

[Translated from DLsite]