The world is becoming warped and overrun by demons. Standing against this tide are the natural enemy of the demons, the 'Onmyoukidou'. Abe is a hard-working, good-natured onmyoukidou of the under-staffed second division defense against the demons. He's relieved to hear that new staff have been assigned to his team, but less so when he meets the rude and violent Yomi and her silent ninja-like partner. Together they must find a way to defend the city from the demons, and to show up the vastly more popular and highly supported first division team.