Nina Yamada wishes to fall in love with a cute boy who will protect her no matter what. In the midst of complaining to her friends, two attractive boys fall out of the sky right in front of her. They introduce themselves as Zero and Ichii—two candidates who are taking a magical exam to become professional wizards. As part of the test, the duo is tasked with finding the "Crystal Pearl" and protecting it for six months from the other applicants. After the examination period, the pair that possess the pearl will automatically become full-fledged wizards.

When the two discover that Nina had accidentally mistaken it for candy and swallowed it, the boys have no choice but to act as her full-time bodyguards for the rest of the exam until an antidote to remove the pearl can be created. Safeguarding a human from their crazy wizard candidate foes is a lot more challenging and exhausting than Zero and Ichii realize. Will they be able to pass the exam while protecting Nina's life?

Included one-shots: Volume 1: Medical Magical Volume 2: Kaitou Papillon