Kekkaishi Vol. 5 (manga)

Karasumori, the magical area that Yoshimori and Tokine have been assigned to protect, is a place of mystery and wonder. Beneath its surface lurks Lord Uro, a fantastic donut-loving creature who only appears when he needs a helping hand with home repairs. Yoshimori has been assigned the task of handyman--the only problem is that Uro's home lies in the depths below Karasumori, where the magic is strong enough to have ill effects on humans.