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.
B-But you're out too, aren't you?
لـ-لكن أنت خسرت أيضًا، صحيح؟
D-Dann bist du aber auch raus!
¡Oye, tú también metiste la pata!
¡Oye, tú también has metido la pata!
M-Ma hai perso anche tu, no?
M-Mas depois disso
você também perdeu!
Так ты тоже, получается, проиграл?!