From ebookjapan:
A fantasy, slapstick comedy featuring a bullied elementary school boy who accidentally summons and befriends a wizard. Already unpopular at school, Honmaru Edojou's life becomes even more difficult when, after a change of seats, he ends up seated next to the worst bully in class. After returning home and rushing into his father's office, he knocks over one the many piles of books and accidentally summons the little wizard Taruruuto. But, it turns out that Taruruuto is the class dunce where he's from, and terrible at magic! Additionally, using magic to help people makes him weak and frail, while using spells that harm makes him healthy and strong. Will Taruruuto's presence turn out to be a blessing or a curse for Honmaru?