Mizuto and Yume used to date, but now they've suddenly become stepsiblings. Both of them agree that they don't want to do anything that'd disappoint their newly remarried parents. However, neither of them can accept the other as being the eldest sibling in the relationship. So they both agree to settle the matter with a game. Whoever does something in conflict with what people might consider normal sibling behavior, loses. Making them the younger sibling.
I can't bear to fight with you any longer.
.لا أتحمّل الشّجار معك أطول من هذا
Ich hab keine Lust mehr darauf,
mich dauernd mit dir zu streiten.
No quiero seguir peleándome contigo.
No puedo seguir peleándome contigo.
Je veux plus qu’on se dispute,
toi et moi.
Non ce la faccio più a litigare con te.
Não quero mais brigar com você.
я просто уже не могу находиться
рядом с тобой.