Mamori Wataya has always faded into the shadows at her school. Tall and plain, she long ago accepted her role as a side character. When she befriends Soushi Fuji, her brusque classmate who walks with a cane and gets even when people underestimate him, a new avenue appears before her. Can Fuji teach her to embrace her bad side and become a villain like him?

When Fuji asks Wataya to drain the school pool for him, she gets her first taste of the high that comes from breaking the rules. Like the villains in anime and manga that Wataya admires, she’s ready to try being a little naughty. Though she may not be ready for drastic crimes, Wataya knows she wants to start doing bad things.