Haruki hears about Kazusa's moving from her mother, who she hadn't been on good terms with.  He feels betrayed and angrily confronts her.  But his words force open the door to Kazusa's heart, which she had desperately tried to keep closed so that the three of them could stay together.
I'll be late, but I'll definitely come.
Ich werde spät sein,
aber definitiv kommen.
Llegaré tarde, pero voy a ir.
Llegaré tarde, pero iré.
Ne t’inquiète pas. Je viendrai, 
mais un peu en retard.
Vou me atrasar, mas com certeza vou.