Having come to Canada upon hearing the fake news that his mother Haruko is in critical condition, high school student Kaidou Haru meets a young boy named Ren and is forced to spend the summer with him.

Five years later, working as a host while saving money for his twin brothers' tuition, Haru's lawyer Mikiko invites him to her office where he is reunited with Ren.

Brothers Aki and Shima are upset by the sudden appearance of a fourth brother in the Kaidou family, and Haru's excessively affectionate attitude towards Ren makes Aki explode with rage.

Spring arrives, and Haru's dream of living with his brothers finally comes true; they move into a house together, and with the help of his former coworker Ikuyoshi, Haru's plans to open a cafe seem to be coming along as well.

Just when Ren begins attending school, he's seen kissing Haru goodbye by his classmate who is curious about their relationship.

While Haru and Ren are out at a nearby zoo, Aki calls Haru to let him know a woman calling herself Kiyoka has showed up at the house; Kiyoka is Haru's high school classmate and the co-owner of the cafe they're about to open.