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.
she should give the piano and the 
room back to us music students.
sollte sie das Klavier und den Raum 
wieder uns Musikschülern überlassen.
debería dejarles el piano y el 
salón a los estudiantes de música.
debería dejarles el piano y a la sala 
a los estudiantes de Música.
deveria devolver o piano 
aos alunos de música.