Mest up. The best love.

Darkest and most messed up love that I ever read but at the same time it so sweet it hurts. It is a story about society where every single person has a type he is born with. Main characters is a girl SHUT (its type that falls in love with one person for the rest of their lifes and its like meeting a mate one look and they know) and a boy who is a DESTRO (violent type that has abnormal strength but are cold as ice killers that like to torture and chop up their victims)