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"...
He's still sleeping in the garage with 
the dogs tonight instead of in his room.
Der schläft immer noch in der Garage mit
den Hunden. Welche Weiterentwicklung also?
Sigue durmiendo en el garaje con 
los perros en vez de en su cuarto.
Sigue durmiendo en el garaje con 
los perros en vez de en su cuarto.
Où tu vois des progrès,
E anche stasera dorme in garage
coi cani, invece che in camera sua.
Que progresso eu obtive com aquele 
 menino que, ao invés de dormir no quarto,