Rebecca "Becky" Miyamoto
The eleven-year-old advisor of Class 1-C and the school's mathematics teacher. Becky was born to an American father and a Japanese mother. She's often cool and collected, but in scary or uncomfortable situations, she acts like a kid her age — immature, spoiled, and quick to hide behind a curtain and cry like the little kid she is at the first sign of trouble.
- Butt-Monkey: Her class sure love making fun of her.
- Child Prodigy: She's an MIT graduate at age ten.
- Cosplay Otaku Girl: Besides her labcoat over blousers and skirts attire, she is also seen in other attires, such as an Elegant Gothic Lolita or on nekomimi-themed pajamas.
- Cry Cute: Whenever she gets scared, pressured and/or scolded by her students (usually by Rei), she hides behind a curtain and breaks down crying like the eleven-year-old kid she is, and usually turning Super-Deformed as well; so cute indeed that Himeko even called it the "Hau-Hau".
- Grade Skipper: Extra exaggerated with Becky already being a MIT graduate and a teacher at age eleven.
- Idiot Hair: In Episode 3, Becky briefly gets one, and she gets so frustrated with hers that she rips Himeko's right out of her head.
- Master of Disguise: She once managed to flawlessly impersonate Mesousa, a Giant Salamander and Sayaka for a whole episode.
- Done as a Call-Back in the OVA, where she impersonated Rei.
- Multicolored Hair: Her hair is part blonde, part pink, presumably reflecting her half-American, half-Japanese ancestry.
- Only Sane Woman: Shares the role with Kurumi and Miyako.
- Sensei-chan: Exaggerated, since she tends to act childish because she's actually younger than her students, being only eleven years old.
- Super-Deformed: Sometimes, usually whenever she cries.
An incredibly energetic girl with an Idiot Hair and a taste for crabs. Her antics often annoy her classmates.
- Idiot Hair: Hers even moves around of its own accord and apparently is the source of her hyperactiveness (when Becky took it from her, she lost all her drive and much of her strength. She use two chopsticks stuck into her hair as a replacement, before she got it back).
- Large Ham: The English dub even pushes it further.
- Motor Mouth: More pronounced in the English dub.
- Trademark Favorite Food: Anything that tastes like crab. Although she has only eaten imitation crab.
- Verbal Tic: She says "Maho" a lot. She also often attaches "Omega" to the beginning of things.
- Wingding Eyes: Gets a perpetual case of starburst-eyes when she's possessed by the mushroom alien.
The cool-headed, calculating think-tank of Class 1-C.
- Gainaxing: In Episode 25.
- The Glasses Gotta Go: People don't even recognize her without her glasses.
- Jerk with a Heart of Gold: She frequently threatens bodily harm to anyone in order to enforce order. She's often the first to try to put Becky in her place should she go too far, but is also the first to try to lure her out should she end up going Cry Cute.
- You Gotta Have Blue Hair: Has dark green hair.
A student in Becky's class obsessed with studying. The most down to earth of 1-C, and often blames the other characters for her failure to study.
- Berserk Button: Don't call her a "study-bug" (Japanese)/"worm" (English).
- Book Dumb: For all her efforts, Miyako still ends up over average. She's often quick to blame her classmates for her subpar performance.
- Forehead of Doom: Current trope image-maker. Miyako's noticeable, shiny forehead has shown to do the following over the course of the series:
- Reflect the sunlight and focus it into beams of energy that set things on fire like a Kill Sat.
- Give instant suntans.
- May require sunglasses to view directly.
- Can act as a police spotlight when chasing after a criminal at night.
- Can easily get wedged and stuck in tight spaces.
- Himeko thinks that it's able to use the shine to kill germs, although it actually didn't work.
- It gets used as a grooming mirror by Himeko. That's just the tip of the iceberg too.
- Informed Ability: According to her Boss Subtitles she has them, one of which was launching beams from her forehead.
- Meganekko: Though she'll sometimes wear contacts instead.
- Only Sane Woman: Often tries to be one with less than optimal results.
Sayaka Suzuki (AKA "Rokugou"/"No. 6")
A kind-hearted (to the point of naivete) girl in Becky's class.
- Mega Twintails: Sometimes Becky refers to Sayaka as "ribbon-head" due to her hairstyle - giant pigtails tied with two large white ribbons.
- Mistaken for Gay: She likes Igarashi-sensei, and the girls of Class 1-C initially assumed she was in love. Turns out her feelings were more about admiration. Then Episode 15 shows a brief moment with Himeko, and Episode 17 shows her handcuffing Miyako so they won't get separated, although some of her classmates suspect something else.
- Naïve Everygirl: To the point that some of her classmates exploit her naivete.
- Not So Above It All: On occasion she can join the gang's antics, and is also shown to snark once in a while.
- Verbal Tic: Sayaka's gimmick in the anime is saying that something is "the ~~ of the year".
- You Are Number 6: Literally. Igarashi-sensei reveals that she's the sixth girl with the surname "Suzuki".
An average-looking girl who doesn't like being called "ordinary." Whenever called plain, she usually fades out of existence and isn't noticed.
- Bokukko: Calls her brother Shu "aniki".
- She even gets turned on by Himeko refferring to herself with "boku" when the mushroom alien possessed her.
- Corner of Woe: Call her "plain" and she'll crawl into the corner of the rabbit hutch gloomily singing "ra-ra-ru...". She's also known to turn invisible whenever a rabbit hutch isn't readily available.
- The Generic Girl: Average in both appearance, academics and sports, although leaning more toward the latter, evidenced by her participating in a basketball tournament in the manga, as well as running in Episode 8. Rebecca calls her "boring girl" when she can't remember her name.
- Genki Girl: Definately has signs of this, as she's seen only trailing Himeko in being quite happy.
- Meido: Works at a Maid Cafe... whose sales aren't doing well because of her presence.
- Meta Gal: On occasion.
- Only Sane Woman: Similar to Miyako and Becky, she also takes the Sanity Ball.
The Class Representative of Class 1-C. She is calm in every situation, but is prone to very erratic behavior.
- Ambiguously Evil: She has a body count for starters.
- Catchphrase: "My name is Ichijou, the Class Representative."
- Chaotic Stupid: What she does may seem evil, or less often good, but often determining what drives her is impossible, especially when some of her actions obviously do not benefit her.
- Hammerspace: She sometimes pulls her sister out of her shirt.
- Interspecies Romance: With the Alien Captain.
- Murder Is the Best Solution: In the first and second episode, she repeatedly tries to poison Becky, insisting that this will solve everything. Rei, being Rei, picks up on this immediately and decides to have Ichijou taken out of the episode. She ends up killing Mesousa at the end of the first episode instead. In another episode, it's also implied that she killed Hibiki when the latter was spying on Becky.
- Nice Job Breaking It, Hero!: On more than one occasion.
- No Name Given: We never learn her first name; the other characters only call her "Ichijou" out of respect for her position. It's hinted at one point that her given name might be "Honey", though.
- Reflectionless Useless Eyes: It's as if her flat brown eyes let nothing in or out; she is always calm about everything happening around her, and we don't get to see what's happening inside her mind.
- Weirdness Coupon: Most of her bizarre behavior is dismissed as "It's just Ichijou."
Becky's pet rabbit.
Advisor of Class 1-A. She is a heavy drinker who often comes hung over.
- Apathetic Teacher: When not suffering from a hangover mid-class, she's often staring through the windows.
- Hard-Drinking Party Girl: She even appears drunken in the middle of her class.
- Hot Teacher: Even if she rarely tidies herself up, she still qualifies.
- The Pig-Pen: Notorious among her students for never wearing make-up, never dressing properly, being frequently tardy or absent, and often reeks of alcohol.
Elder of the Kashiwagi twins, whom Igarashi-sensei frequently confuse as one person.
- Berserk Button: Doesn't like the prospect of Igarashi-sensei referring to them as though they're a single person.
- Polar Opposite Twins: Energetic and outgoing, in contrast to the introverted Yuna.
- Signature Headgear: She's distinguishable by the blue ribbon on the left side of her head.
Younger of the Kashiwagi twins.
- Polar Opposite Twins: Shy and reserved, in contrast to the extroverted Yuma.
- Signature Headgear: She's distinguishable by the red ribbon on the right side of her head.
Kurumi's older twin brother. A laid-back character and a skilled chef.
- Butt-Monkey: Not as severe as his younger sister, but on occasion he still gets treated like a servant.
- Real Men Wear Pink: He is a good cook.
- Team Dad: In the event Igarashi-sensei is too drunken to handle the class.
A bumbling girl and member of the Intelligence Department and the Film club.
The advisor for Class 1-B and PE Teacher.
- Covert Pervert: Becky once claimed he only became PE teacher to bask at the sight of girls in bloomers.
- Limited Wardrobe: Rarely (if ever) seen without his trademark tracksuit.
A tall, athletic girl from Class 1-B.
A stature-challenged girl who often hangs out with the tall Suzune.
- Butt-Monkey: Frequent prank of height jokes from Suzune, who even holds her and presses a pressure point on her head in order for her to stop growing. But Suzune always touches the one that induces diarrhea instead.
Leader of the Intelligence Club.
- Intrepid Reporter: Especially tries to cover "scoops" regarding Becky and her own class.
- The Rival: Considers Rei to be her rival.
- They Killed Kenny Again: Sometimes her reports end with her "death", only to come back alive and well each time.
- Those Three Girls: With Yuzuko and Akira.
The only known male in Class 1-B.
A masculine-looking female.
The elderly advisor of Class 1-D and literature teacher.
- Couch Gag: The armband on his left arm shows a different text in every episode.
- Cut His Heart Out with a Spoon: In episode 1 he threatens his own class with haunting them should they leave class to see Becky, who has just arrived at that time.
- Everyone Calls Him "Barkeep": Subverted. That's actually his name.
- Only Sane ManOld Geezer: "Aren't there any sane person in this class?"Tsurugi: "Look who's talking."
A cosplay-obsessed girl and a member of the Drama club.
- Cat Girl: Not really, but she's got two parts of hair that stick up like cat ears.
- Enemy Mine: Best friends with Kurusu, unaware that she's a member of the Film club, the Drama club's mortal enemy.
- Master of Disguise: At one point, she even posed as Becky herself.
A "magical girl" from Class 1-D.
- All-Loving Hero: Becky even asks her to ask herself if she really believes herself to be a Magical Girl or just wants to help others.
- Chuunibyou: She constantly dresses and acts as though she's a Magical Girl. She eventually grows out of it.
A mysterious girl sent to Momotsuki High to keep an eye on Becky.
- Multicolored Hair: Her hair is part blonde, part green.
An animal-loving blonde student.
- Tsundere: She usually doesn't get along with Tsurugi and can't understand his cavalier behavior towards her menagerie of pets, but always asks for his help in finding any lost pet.
A white-haired, serious student.
- But Not Too Foreign: Has a German grandfather.
- Friend to All Children: Lampshaded in his introduction. Highlighted when he helped Nozomi find Ichijou.
- Jerk with a Heart of Gold: He frequently criticizes Misao's strange menagerie of pets, but is nevertheless willing to help her find lost pets.
- Sugar-and-Ice Personality: Despite his cool exterior, he's a calm, gentle boy who loves little children.
A clumsy student of Class 1-D and member of the Intelligence Club.
- Those Three Girls: With fellow Intelligence Club members Hibiki and Kurusu.
A mysterious feline entity whose residence is the school's vending machines. No relation to the Internet Reviewer of the same name.
- Cloudcuckoolander: Besides thinking he's God, he hides in vending machines to warm sodas with his body heat.
- Verbal Tic: In the Japanese version, he often says "desu nya" at the ends of sentences. "Nya" is Japanese onomatopoeia for the sound cats make; accordingly, in the English dub he says "Meow" instead.
- Voiced by: Ai Nonaka (JP and EN)
Ichijou's infant younger sister.
- No Name Given: In the anime. The manga reveals that her first name is Nozomi.
The leader of a group of aliens that observe Becky and the students of Momotsuki Academy.
- Actor Allusion: Appears as Captain Picard in the last couple of episodes. Mugihito voiced Picard in the Japanese dub of Star Trek: The Next Generation
- Everyone Calls Him "Barkeep": He is only known as "Captain".
- No Need for Names: Has absolutely no idea what his subordinate's names are.
A... subordinate of the Alien Captain who often snarks on their situation.