Two high school girls who are about to graduate also happen to be highly-skilled assassins. When the organization they work for orders them to share a room, their relationship quickly sours. But when they become targets of the yakuza, the girls realize they'll have to work together to survive.

Chisato and Mahiro must pay four years of overdue fees or lose their membership in their assassin guild. They take part-time jobs, but find themselves in the middle of an armed robbery and being hunted by other assassins.

Teenage assassins Mahiro and Chisato visit the coastal city of Miyazaki for a contract and a vacation, but they unexpectedly cross paths with a legendary, bloodthirsty assassin looking to add to his kill count.