Spoilers below. The premise was very unique; a disease in which you can't see individuality. A boy who is thought to be the only person in the world with this disease rejoices, as he finally gets the chance to be seen as special- until another girl shows up with the same disease. And so the boy decides the most reasonable thing to do is not console her, but to kill her off before she dies of said disease. The bloodbath commences. I really enjoyed this manga, it provides surprisingly great commentary on what it means to be an individual; that you should embrace your characteristics regardlessif you share them with other people.