Hijiri, Youichi

Yōichi is attached to Natsume, though he initially appears to dislike Mikan. Later, he grows attached to Mikan and even kissed her on the cheek once. He eventually begins to "cling" to her as the manga progresses. He has also become very fond of Mr. Bear.
He possesses the Alice of summoning bad spirits, which is a Dangerous Ability type. He is remarkably bright for a three-year-old. Natsume likes him because he feels the boy is just like himself, and Natsume is also helping Yōichi to be transferred out of the Dangerous Ability class.
Like Mikan, he loves "Fluff Puffs" (Howalon in Japanese), the best-selling candy in Central Town.
During the Hana Princess arc, he accidentally ate an aging candy that he had stolen from Hotaru, which granted him an ability that turns him into a 13-year-old. The side effects gave him the ability to switch between his younger and older self. He retains the mind of a 3-year-old when he changes his age, which creates awkward situations for Mikan because he likes hugging and carrying her.
He is the youngest member of the Dangerous Ability Class and is a Single Star student.
He also appears in M to N no Shōzō as Eiichi Hijiri's younger brother.