Having come to Canada upon hearing the fake news that his biological mother Haruko is in critical condition, high school student Kaidou Haru meets a young boy named Ren. "You have a new brother. Take care of him." So instructed by his mother, Haru is forced to spend the summer with Ren. Every day is a battle with Ren, who refuses to listen to anybody. However, as Ren grows to like Haru little by little and Haru comes to adore Ren as well, they make a certain "promise"...
I'd like it if you'd sleep here with me.
Würde mich freuen, wenn du mit deinem
großen Bruder zusammen schläfst.
Quisiera que durmieras conmigo.
Me gustaría que durmieras conmigo.
Ça me ferait plaisir
que tu dormes avec moi.
Mi piacerebbe che dormissi con me.
Ficaria muito feliz se você dormisse
junto com o seu irmão mais velho.