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 get my heart ripped out 
in front of me every day...
Mein Herz wird mir jeden Tag herausgerissen,
wenn ich dich sehe.
arrancándome el corazón 
frente a mí todos los días?
Me has pisoteado el corazón todos los días...
Tu me fends le cœur, 
jour après jour…
Vejo meu coração se destruindo diante
 dos meus olhos todos os dias...