Voiced by: Kaori Fukuhara (JP)
- Ahoge It's likely caused by her bangs being pulled back. In the first episode, Nagi compares it to a Parakeet.
- Attention Deficit... Ooh, Shiny! An airhead.
- Blank White Eyes: She has them almost 50% of the time.
- Bob Haircut Very short hair with her bangs pulled back.
- Kuroda even notes in his end of volume 1 supplement that, within that volume, She started off as an airhead and over time became simply crazy.
- The Ditz She isn't very aware of her surroundings and needs Tooru's help sometimes. She's the only one who doesn't realize how creepy Mr. Satou is.
- Dumb Blonde Not exactly dumb but very airheaded.
- Expy: Of Tsukasa. Both are sleepyheads and both are ditsy.
- Going Commando: Once Run forgot her panties on her way to school. Tooru: "Don't worry people forget things... Usually not their panties though." Run: "Just now you thought, usually not their panties right?!" *Runs away* Tooru: "Run wait! Your panties!"
- Gratuitous English: In episode 3. "No Music No Life" and "Mada (still) No Music Life"
- Heavy Sleeper Often seen tired.
- Hidden Buxom
- Idiot Hair
- Insane Troll Logic: One of her many ways of misinterpreting the world.
- Lethal Chef
- Nice Girl Tooru's best friend and she doesn't even realize how creepy Mr. Satou is. Run is never seen angry.
- Oblivious to Love: She seems to be cheerfully unaware of Tooru's feelings for her, and is the only one in the cast who doesn't find Satou's obsession of her forehead creepy.
- Show the Forehead: At one the point Nagi didn't even recognize her with her hair down.
- It turns out to be the new health teacher, Satou's Fetish.
- Tareme Eyes To show her airheaded personality.
- Too Dumb to Live: Her friends literally have to keep her from hurting herself. (But we still love her anyway.)
Voiced by: Aoi Yuki (JP)
- Batter Up She uses this to protect Run from guys.
- Berserk Button: Her diminutive size.
- Bob Haircut Very short boyish hair just like Run.
- The Caretaker: She is very protective of Run.
- Clingy Jealous Girl: With regard to Run she doesn't like it when other people talk to Run but she eventually learns to share her friends.
- Dull Eyes of Unhappiness: When Yuuko inadvertently irritates her.
- Hammerspace: When She has her shirt hanging out of her bloomers, it looks like she's just wearing a dress (it goes past her knees), but when it's tucked in...nothing.
- Nonuniform Uniform: Almost always wears a purple cardigan with extra long sleeves over her school uniform. In episode 6 Run convinces her to take it off, and she swaps it for a purple vest.
- Older Than They Look: Emphasised in episode 5, when she wears swimsuits for elementary schoolers... She's very short and has a flat chest.
- Pet the Dog: She's fond of small animals and children, often giving kids candy. Also she is a great help in the classroom.
- She finds Yutaka annoying, but she's perfectly fine with showing the girl her notes or helping her with problems.
- Yuuko on the other hand...
- School Swimsuit: She's had the same one since elementary school.
- Short Dark And Bishoujo: How Yutaka and Miho sees her.
- Sitcom Arch Nemesis: She just doesn't like Yuuko.
- Sweet Tooth Sweets are the way to get her to do a favor. Tooru sniffs out an empty candy bag that Run was sharing with her friends. Run buys two donuts to make up with her after a fight. Earlier while separated from Run, Tooru drowns her sorrows with canned juice.
- Token Mini-Moe: And she not to happy about it. She had to stand up on a chair to scare away boys bothering Run. She wants to be Adult like.
- Tsurime Eyes It represents her cold personality.
- Tsundere: Nagi describes her as this, Run forgets what one is and imagines her with a spear. Tooru acts cold and serious but she's a good caretaker to Run and she secretly enjoys Yutaka's company.
- Zettai Ryouiki: Although they tend to slide down since she's so skinny.
Voiced by: Minako Kotobuki (JP)
- Butt Monkey: Tooru is the main culprit, but nearly everyone constantly makes fun of her/has fun at her expense.
- Catch Phrase: She has Nani?, usually said when she ends up as the Butt Monkey.
- Covert Pervert: At least once:
Yuuko, when handed a hentai manga with a character that resembles her.
Yuuko: I don't like this kind of stuff.
Nagi: You say that, but you're reading the whole thing...
- She also tried to sneak a peek after being told Run had accidentally left home pantieless.
- Expy: She is VERY similar to Mio. Ironically, she is voiced by Minako Kotobuki who voiced Mugi.
- She's got a bit of Mei, too.
- Girls Are Really Scared of Horror Movies Tooru tries to get her to watch them but she really doesn't want to. She is also scared of ghosts and the dark. She has to sleep with a stuffed animal during the night the four of them sneaked into school.
- Godiva Hair: Just barely covering.
- Hartman Hips
- Huge Schoolgirl Reaching 170cm which she isn't happy about.
- Kansai Regional Accent
- Rapunzel Hair: It comes down to her hips. She has the longest hair out of everyone in the show.
- Shrinking Violet She is a bit shy and hates horror movies.
- Tall, Dark and Bishoujo: But she's not pleased with the attention.
- Tsurime Eyes
Nagisa "Nagi" Tennōji
Voiced by: Yumi Uchiyama (JP)
- Between My Legs: In episode 2 when she tells Yuuko to quiet down in the bath.
- Brainy Brunette Very Intelligent and is seen reading sometimes. Her hair is brown.
- Expy: Of Yomi. Both struggle with weight gain and both are the straight man. It helps that they both have a very similar appearance. Brown hair and nerdy glasses.
- Girlish Pigtails They don't look very childish though considering how mature she is. They were likely there for her nerdiness aside from trying to look plain.
- Hachimaki: She wears one when preparing for her New Years diet.
- Meganekko Is blind without them, mistaking mannequins for people. Her pigtails and glasses make her look like a nerd. She also looks cute with glasses on.
- Nonuniform Uniform: Usually wears a beige cardigan over her school uniform, except during the summer. Instead she has it tied around her waist.
- Not So Above It All She's the one who suggests they sneak around in school at night.
- Princess Curls: During the Festival Episode she curls her twin tails but is a little embarrassed about it. Run thinks it's cute.
- Serious Business: She takes the Ibod very seriously.
- Scary Shiny Glasses Sometimes especially when teasing Yuuko.
- Straight Man Comments on how foolish the others antics are but sometimes she likes to join in.
- Tsurime Eyes: Under her glasses that is.
- Weight Woe Although she looks normal.
Voiced by: Ai Matayoshi (JP)
- Book Dumb She has to rely on Tooru. When wishing Tooru a happy birthday, she misspells birthday.
- Eyes Always Shut: Most of the time. She opens them when Tooru and Miho get worried about her safety after insisting on climbing the school tree to save a cat stuck up there.
- Third Person Person: Though the subs don't show it, at first. It shows her childishness.