Kumiko Aikahara: 18 years old, orphan, single. After her grandfather'd recenty died of heart failure (cough, yagami light), she was told to go to Edo to live with an old student of his. It turns out he's the commander of the great police force that roams around the big city! There she meets the demon vice chief, Toshiro Hijikata, just to find out he was an inimical, over serious, mayonnaise lover. Along with him, she encounters Sougo Okita (also known as the 'sadist king') where Kumiko discovers that he also shares a great dislike towards Hijikata. With their mutual hatred towards Hijikata, the two join forces to cause him pain. (The story sucks at first, but I swear it gets better).