Hisao's life was that of a normal Japanese high schooler until one day while being confessed to by a girl he liked he suffers a heart attack. It is determined that he has heart arrhythmia and spends a few months in a hospital before it is determined that he can leave with a regimen of medicine to keep him alive. However, since his condition is serious he isn't able to return back home and his parents decide to make it easier on everyone that they he will be enrolled in Yamaku High School, a school for kids with disabilities.
Hisao doesn't take the news too well, but doesn't have a choice in the matter. At first he struggles with trying to fit in with the new school as he doesn't know how he should interact with the other students and except his new life with a serious illness. He soon finds himself making friends with some of the girls in the school and a strange boy, Kenji. As he continues his new he will have to continue to manage his condition, work on his studies, and maybe even find love in one of the girls at the school.