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.
To be honest, I've pretty much given up 
on getting you to listen to a word I say.
Ehrlich gesagt habe ich schon aufgegeben zu glauben, 
dass du meinen Worten Gehör schenkst.
La verdad es que casi me rindo 
intentando que me escuches.
La verdad, estoy a punto de tirar 
la toalla en esto de razonar contigo.
Para ser sincero, 
já praticamente desisti