Super Lovers follows Haru Kaidou, the eldest son of the Kaidou family, whose life changes when he flies to Canada after hearing that his mother is on the verge of death. Instead of the crisis he expects, Haru discovers that his mother has fooled him and that he is now responsible for Ren Kaidou, his adoptive brother: an antisocial boy who feels more comfortable around dogs than people.
As Haru tries to understand Ren and build a place for him in his life, the two gradually grow closer. Haru makes Ren a promise: once he graduates from high school, they will live together in Japan. That bond is later shaken by an accident that leaves Haru without any memories of the summer they spent together, including the promise he made. Five years later, Ren arrives in Tokyo expecting Haru to keep that promise, but to Haru he is only a stranger claiming to be his brother.
Super Lovers turns that reunion into a quiet but tense family drama, following the fragile trust between Haru and Ren as they navigate memory, responsibility, and the future they once imagined together.