Mikan is the protagonist of the story. She is a cute, energetic, good-natured girl, but her clumsiness lands her into trouble. She is a very up-an-at-it and athletic person, much to annoyance of her down-to-earth friend, Hotaru. She used to live with her grandfather in the countryside.
She was shocked to hear that Hotaru was moving back to the city to go to an academy for young ‘geniuses’ like her. When she heard rumors that students were like slaves in Alice Academy (which she felt was a possibility, since they gave money to parents for sending their children to the school), Mikan left her grandfather and her home to go after Hotaru by herself. She was then accepted to Alice Academy by Narumi-sensei and could attend Alice Academy with Hotaru and many other children with extraordinary powers.
Her Alice is Nullification, which can resist the effect of Pheromone type Alices and completely negate the powers of other Alices in close proximity to her.
She also possesses the Stealing Alice that can steal alices and turn them into colored rocks, which she inherited from her mother. Both of her Alices are very rare and special.
She once belonged to the Special Ability Class. Later, she gets transferred to the Dangerous Ability Class, and becomes the Elementary Principal’s precious favorite. She is currently a Single Star, but it’s most likely changed to Special Star due to the fact she is highly favored by the principal.
Throughout the story, she has a lot of effect on Natsume and Ruka, who have both started to fall in love with her. As the story progresses she becomes liked and admired by a lot of the people that used to feel uneasy about her Alice. Even her relationship with Hotaru grows stronger. Her name means “Mandarin Orange” in Japanese.
After she loses her Alice Mikan is forced to leave Academy and have her memories erased to assure that no one in the outside world will try to target her to gain information about the school. Not knowing anything about the fate of Natsume and Hotaru she goes back to her grandfather, but she’s allowed to take Bear with her under the condition that it will not reveal it’s true nature to anyone.
Four years later, Mikan is a highschool student and lives peacefully in the country protected by Shiki’s barrier. One day Mikan is targeted by unknown people and is saved by Narumi. At the same time one of her captured and supposed childhood friends is revealed to be Hijiri Goshima in disguise. Confused, Mikan has some flashbacks but doesn’t seem to remember anyone clearly. She stumbles just to find Natsume right behind her back.
In the epilogue, it shows that Mikan and Natsume continue their relationship and get married.