After losing a war with the Virtues, the Sins were tied to two gauntlets they made for mortals to use. This caused them to lose their corporeal form. When a Host puts on a gauntlet, the Sins have to obey that Host. In order to retain universal balance, all Sins have to be unlocked once a Host is chosen, by either an easy or a hard way. If the Host dies, any Sins tied to the Host at the time will die as well.
The comic follows the lives of the Sins and various hosts, during their struggle to survive and keep the balance of the universe, while avoiding various beings they have ticked off during the aeons.