Young Mikan runs away to Tokyo to follow her best friend, Hotaru, who has been enrolled in an exclusive, secretive private school for geniuses. But it turns out that Alice Academy is a lot more than meets the eye. If Mikan wants to stay by Hotaru's side, she has to both pass the strange "entrance exam" and face the even greater challenge of befriending her very odd new classmates. Whether it's Hotaru's gift for inventing gadgets, the cranky Natsume's fire-casting ability, or Professor Narumi's control of human pheromones, everyone at the school has some sort of special talent. But what ability, if any, does Mikan possess? Mikan is going to have to rely on her courage and spunk if she's going to stay in school, or even stay alive! 
(Source: Tokyopop) 
Volume 9 contains a side story; Volume 10 contains the side story "Ibara no Sono" (いばらの園); Volume 17 contains the side story "Hoshizora Obake" (星空おばけ).

Sakura Mikan and Imai Hotaru are best friends, and Mikan is shocked to find that Hotaru is transferring to a school in Tokyo for gifted students like her - Alice Academy. Mikan hears rumors that the students are like prisoners there, and worried what would happen to Hotaru, she runs away to head to the school herself. She finds out all the wonderful things about this school. And she heads into a great adventure!!

His name is sometimes mistranslated as Matsumoto Hiroshi.

Jinno