Voiced by: Rihoko Yoshida The titular character and a new teacher at Arama Academy.
- Adaptation Dye Job: Blonde in the manga, while auburn in the anime.
- Betty and Veronica: Betty to Madoka's Veronica for Kenta.
- Even the Girls Want Her: Very popular among the female students.
- Hot for Student: Kenta has crush on her (and bullied her) as much as he does to Madoka. Other boys also like her with a varying degree.
- The Gadfly: "I give up!"
- One Head Taller: Two heads taller than Kenta. One head for Mr.Yamagata.
- One of the Boys:
- Vitriolic Best Buds: With Kenta.
- Zettai Ryouiki: In some of her outfits.
Voiced by: Masako Nozawa
Machiko's number one troublesome and perverted student.
- Adaptation Dye Job: Black-haired in manga. Brown-haired in the anime.
- Book Dumb: Usually gets horrendous grade (and gets scolded by his mother).
- Clingy Jealous Guy: Does not take it well when Machiko becomes involved with another guy (this includes his friends).
- Disguised in Drag: Frequently cross-dresses in many of his schemes. He is actually proud of it.
- Enemy Mine: Willing to temporary cease his rivalry with Mr.Yamagata whenever both of them have to go against other guy involved with Machiko.
- Handsome Lech: A rather attractive boy for his age, and the most perverted one.
- Jerk with a Heart of Gold
- Vitriolic Best Buds: As much as he plays trick on Machiko (and she retaliate), they also get along very well.
Kenta's main circle of friends at Arama Academy.
Takao "Kame" Kameyama
One of Kenta's friends who has crush on him.
- Action Girl: Frequently engages in sport with strength and skill that rivals the boys.
- Acrofartic: Being overweight doesn't slow her down a bit.
- Nice Girl: While she does enjoy giving the boys a taste of their own medicine, Maruko doesn't go as far as to humiliate them with their own naked photos unlike the other girls.
One of Kenta's friends and the class Madonna.
- Betty and Veronica: Veronica to Machiko's betty
One of Kenta's friends who likes Hiroshi.