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.
So why are you blaming everything on me?
Weshalb gibst du dann mir 
für alles die Schuld?
Entonces, ¿por qué me gritas...
Entonces, ¿por qué me gritas?
Alors, pourquoi je devrais 
subir tes reproches ?
Então por que você está gritando comigo?