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.
An older sister is always supposed 
to protect her little sister first.
Versteht sich doch von selbst, dass die
große Schwester erst die kleine rettet.
Una hermana mayor
siempre protege a su hermana pequeña.
Una hermana mayor
siempre protege a su hermana pequeña.
C’est bien normal,
tu es ma petite sœur !
Una sorella maggiore deve sempre pensare prima
a proteggere la propria sorellina!
Uma irmã mais velha tem
que proteger a mais nova.
Старшая сестра всегда
спасёт младшую!