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 don't care if her guardian 
is a famous pianist,
Es interessiert mich nicht, 
ob ihre Mutter eine Berühmtheit ist ...
No me importa si es una pianista famosa
Me da igual que sea una pianista famosa,
Je sais que sa mère, 
une célèbre pianiste,
Não me interessa se a responsável
por ela é uma pianista famosa,