Kezuru, a first-year junior high student, transforms into a wizard upon discovering the "Mazica Party" card game, where scratching cards summons creatures known as Mazins. His striking appearance includes dark cyan eyes and an undercut hairstyle layered with magenta, cream, and blue hues, paired with a crisp white shirt and vibrant yellow-and-magenta shoes. As a wizard, he dons a long black robe adorned with jagged hemlines and bold red-and-green linings.

Thrust into the role of a destined hero, he confronts challenges head-on, forging alliances with allies like Ballonya—his primary Mazin partner—and others met on his journey. Invited to Mazica Academy, a magic school demanding rigorous trials, he must secure a fused Mazin to prove his worth. His path escalates as he clashes with adversaries like the Legendary Seven Mazins and Dragocastle, a dragon-themed guardian wielding destructive power.

He competes in the Mazica Battle Tournament, hones strategies to deepen bonds with his Mazins, and combats global threats like ancient curses and encroaching darkness. His growth includes achieving a fused state with Ballonya and navigating alliances with figures such as Anya, a girl shrouded in mystery linked to the academy, and Eric, the pragmatic student council president.

Unique among wizards, he holds contracts with multiple main partner Mazins—a rarity in the lore. His name, rooted in the Japanese "kezuru" ("scratch" or "shave"), mirrors the card-scratching mechanic central to his magic. The narrative charts his evolution from an ordinary student to a pivotal warrior balancing light, darkness, and the fate of his world.