In order to cheer Haruto up after his anime was such a flop, Itsuki gets him as well as Nayuta, Miyako and Chihiro together so they can play a TRPG. Itsuki usually plays girls in games, but for some reason, Chihiro makes out their character to be Itsuki’s character’s little sister, which leads to Nayuta and Miyako also making their characters sisters of the other two. Haruto becomes the GM and does whatever he wants.
You there. Stop trying to predict 
what's going to happen.
Okay, das reicht! Story prophezeihen
durch Meta-Infos ist verboten!
Deja de intentar predecir qué pasará.
Deja de intentar predecir qué pasará.
Toi, interdit de faire
des pronostics sur le scénario !
Basta! Smettila di fare del metagioco!
Ei, ei. Vamos tentar parar de
prever o que vai acontecer.
Так, стоп!