Yukari Sendo is one of the smartest students at Yōkai Academy, and the youngest at age 11. She is a witch, and always wears a typical witch costume (consisting of a hat and cape), which is considered by some students to be a violation of the school rules. As a witch, she has problems with her classmates discriminating against her (in the series, witches are viewed as "border beings", those that are something between humans and the supernatural, as it is impossible to tell their difference by appearance alone). Despite ranking #1 on the examinations, she was a lonely prankster before meeting Tsukune and Moka. She initially hates Tsukune, claims that she has fallen in love with Moka, and uses her magical powers to try to drive them apart. However, after both Tsukune and Moka save her from bullying classmates, she falls for him too. Her obsession with both has driven her to try to create a three-way relationship between them. She's the only girl of the group to actually kiss Tsukune. Yukari has, on occasion, developed some bizarre items, often leading to hilarious results or farfetched situations. Items she has developed includes the Horehore kun "Mr. Love-Love" Suku Suku Drops,and Ishin Denshin.
Yukari's parents, both highly skilled and adept in magic, appear during the start of the school festival seen in the anime adaptation, when they repair the torn-up academy.