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 can't get to one from here, can he?
Aquí no recibe ninguna, ¿no?
Aquí no recibe ninguna, ¿no?
Y a pas d’école dans le coin, non ?
Vivendo qui non può
frequentarne una, vero?
Não dá para ele frequentar 
 uma morando por aqui, né?