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"...
You really are just like your father 
when it comes to things like that.
Du ähnelst bei so was wirklich deinem
Vater. Ist es der japanische Charakter?
Eres igual que tu padre con esas cosas.
Eres igual que tu padre con esas cosas.
Tu tiens vraiment ça
de ton père.
Sei davvero come tuo padre
quando si parla di queste cose.
Você realmente puxou o seu pai 
 quando se trata dessas coisas, hein?