Naho got into a fight with Kakeru on New Year's Eve, and never managed to apologize to him before he passed away. At least, that's what the letter from the future says. However, Naho now believes that she's capable of dealing with whatever may come up, and faces New Year's Eve head-on.
there might've been a future 
where he married Naho.
أنا واثق أنّه وناهو سيكونان متزوّجان
 .ويكون لهما مستقبلٌ معًا
dann hätte es auch eine Zukunft gegeben,
in der Naho ihn heiratet.
Naho aurait pu se marier avec lui.
probabilmente ora sarebbe lui
quello sposato con Naho.
A Naho poderia ter escolhido se casar
 e construir um futuro junto dele.
мы могли бы жить в будущем,
где он женился на Нахо.