a-k.com/story

A girl, the last surviving member of a certain family, and a boy who shouldn't exist, a half-ghast.

This is their story.

The half-ghast boy, Akihito Kanbara
was walking home from school one day when he saw a girl on the rooftop, about to fall.

Her name was Mirai Kuriyama.
She was the last survivor of a peculiar family of xenors who were cursed with a strange sort of blood.

An unchanging club. An unchanging life. An unchanging world.
That's how their lives should have gone.

But when that last-surviving girl met that half-ghast boy - their worlds changed.