Childhood friends Isuzu Rin and Yuuki Karen are always together, but every time they open their mouths they get into a fight.... But they are connected by a secret. In truth the two are fighting day and night against a enemy - the Fatals - beings that manipulate emotions to drive people into despair. But now there's a mysterious transfer student, an enemy that knows the secret of Rin's body, and someone at school has taken an interest in Karen?! With many ups and downs, the stylish action duo Rin and Karen begin their story!