A young man troubled by a constant following of spirits and monsters.
A normal teenager at first glance, Watanuki is in fact an orphan who suffers from a constant stream of spirits and monsters being attracted to him. One day he stumbles upon Yuuko's shop and is drawn in by a mysterious power. He presents his wish to not have to deal with the spirits anymore to Yuuko, and she agrees to grant it in exchange for him working for her for an undetermined amount of time. From then on he works as her errand boy, and sometimes even conducts her investigations. He also begins to spend more time with Shizuka Doumeki, whose presence repels demons-- although he considers Doumeki a rival for his crush, Himawari.
Easily shocked and frustrated, Watanuki is independent-minded and hates being in debt to Yuuko and dependent on Doumeki. He seems to have no romantic or sexual interest in Yuuko in spite of her beauty, and is unfazed by her teasing, his attentions focused entirely on Himawari.