Katawa Shoujo

A free visual novel about girls with disabilities. The main character, Hisao Nakai, is an ordinary high school student in his last year. One day he finds a letter from an unknown sender in his locker and comes to the indicated meeting place. The author of the letter turns out to be a girl who loves him, but when talking to her he loses consciousness.

Waking up in the hospital, he learns that the cause of his fainting is an unexpectedly manifested heart disease — arrhythmia. After a long treatment in the hospital, he is forced to transfer to the Yamaku school, where, despite the difficulties, he finds friends and love.