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.
Sorry, Yume. I think I'm gonna be home late today. It seems like 
Mineaki-san is gonna be late too, so tell Mizuto-kun for me, will you?
آسفة يا يومي
.أعتقد أنّني سأتأخّر في العودة للمنزل اليوم
يبدو أنّ مينياكي-سان سيتأخّر أيضًا، لذلك 
أخبري ميزوتو-كُن بذلك رجاءً
Sorry, Yume, wird heute später.
Bei Mineaki-san auch,
also gib Mizuto-kun Bescheid!
Lo siento, Yume. Creo que hoy volveré tarde.
Mineaki también llegará tarde, así que avísale a Mizuto, ¿sí?
Lo siento, Yume. Creo que hoy volveré tarde.
Mineaki también llegará tarde, así que avisa a Mizuto, ¿vale?
Mineaki et moi allons rentrer plus tard,
aujourd’hui. Préviens Mizuto.
Scusa, Yume. Credo che oggi tornerò a casa tardi. A quanto pare
anche Mineaki-san farà tardi, per cui avvisa Mizuto-kun, ok?
Desculpa, Yume!
Acho que vou chegar tarde em casa hoje.
Parece que Mineaki-san vai se atrasar também,
então avise o Mizuto-kun, tá?
Юмэ, извини. Сегодня приду поздно. Видимо, Минэаки
тоже задержится, так что передай Мидзуто, хорошо?