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.
You've got to start work on the 
Miss Houjou contest in April,
Du musst mit der Arbeit für den 
Miss-Houjou-Contest im April beginnen,
Debías empezar con el concurso 
Señorita Houjou en abril
Deberías empezar el Miss Houjou en abril
Pour le concours 
de beauté du lycée,
Você precisa começar a trabalhar no
concurso da Miss Houjou ainda em abril