Haru Kaidou and his adopted younger brother Ren share a household after Haru brought the withdrawn boy back to Japan to raise him. This second season opens with the return of Haru's mother Haruko, who intends to take Ren back to Switzerland, forcing Ren to confront how he wants Haru to see him. Natsuo Shiba, a cousin of the Kaidou siblings, turns up around the house while that question hangs over it. The season continues directly from the first and stays centered on their evolving bond.