Histoire
The story centers on an 11-year-old boy who hates the lack of unique individuality in the world, and hates that he himself lacks individuality. One day, he finds that everything that might give a person individuality — such as their faces, names, and personal information — have been erased from his sight, as if by a marker pen. He later learns that this is a fatal disease, and that he will not live past 12.
Synopsis via AniList (en anglais).