Main characters ; : : Yūko (or Yuuko) is an energetic sixteen-year-old high school girl with short brown hair. Yūko's main desire in life is to make every day more fun and interesting than normal, often at other's or her own expense. Because she is often too lazy to do her own homework, she always copies from either Mio or Mai instead. Although she is a generally easygoing person, her mood changes instantly when she is insulted. She often greets people with her catchphrase "
selamat pagi" (Malay and Indonesian for "good morning") in a bid to make simple greetings more interesting. ; : : Mio is a bright and cheerful girl with pastel-blue hair pulled into
pigtails and held by two small wooden cubes, which are her most identifiable feature. She has a crush on Kōjirō. Though ordinary-looking in comparison to her friends Yūko and Mai, Mio harbors a very short temper, prone to tantrums and acts of violence in order to avoid humiliation, even assaulting a police officer to keep her
yaoi manuscript from being discovered. She often has to humor Yūko to make her happy. Being a talented artist, she occasionally draws homoerotic pictures of Kōjirō in her notebooks and, under a male pseudonym, has entered several erotic manga into contests that promise serialization to the winner. Near the end of the manga, Mio finally wins one of the contests she entered, though it is unclear if she actually accepted the publisher's offer due to her paranoia about her art. She is sixteen years old. Accordingly to a daydream of Yūko's, the cubes in her hair are supposedly magical artifacts from a Fey Kingdom
zeppelin that fell on her head. Mio has minor appearances in
City. Here Mio is a mangaka artist who is only referred by the pen name of "Daisuke" and is a very successful and famous manga artist. ; : : Mai is a quiet and intelligent girl who wears glasses. Before the events of the manga series, Mai had lived in
Alaska and moved to
Japan due to her father's job. Likely as a result of this, Mai is fascinated by
Shinto shrines and will always visit whenever she sees one. She excels at a wide range of activities, including fishing, wood carving, and arm wrestling. Despite her serene and rather unemotional demeanor, she has an eccentric sense of humor and will often provoke Yūko with a variety of gags in order to gauge a reaction out of her, much to Yūko's chagrin. She has two pet dogs named Oguri Cap and Pyon. ; : : Nano is an android schoolgirl, built by the Professor. Despite being a year old, she has the height and appearance of an average teenager. She worries about keeping her identity as a robot from other people, even though the large wind-up key on her back makes it quite obvious. Her limbs will sometimes fall apart, revealing items that the Professor installed into her system without her noticing, ranging from beam-firing weapons to
Swiss rolls. She acts like the Professor's caretaker, and spends her days helping her and doing all the household chores. Nano's main goal in life is to go to school, which the Professor eventually grants, resulting in her befriending Yūko's group of friends. Although she was technically never born, her "birthday" is March 7. ; : :The Professor is an intelligent eight-year-old scientist. She built Nano herself, and often makes various adjustments to her, but adamantly refuses to remove the wind-up key on her back because she thinks it is cute. Her favorite animal is the shark. She does not go to school, since she already graduated, and instead spends her days playing around in the house. Despite her intelligence, she acts like a spoiled child most of the time, as she throws tantrums to get what she wants. She likes snacking, playing around, and sharks. She also enjoys spending time with Nano's friends, particularly Yūko due to her approval of "cool things" and Mai because she gives her shark-themed chocolates and drawings. She didn't like Mai at first because she let her dogs corner her and Sakamoto on the street, but warms up to her when Mai draws a shark for her. ; : : Sakamoto is a black cat. He wears a red scarf made by the Professor, which allows him to speak. He was originally named Taisho and was Kana's pet until he fell out of the window of her house. He was then found by the Professor before mysteriously turning up at the Shinonome Lab. He decided to stay with Nano and the Professor because of his relative luxury at the home in contrast to Kana's constant unintentional neglect. In
cat years, he is 20 years old, older than both Nano and the Professor, and tries to act like the adult of the house, but he occasionally succumbs to his shameful catlike habits. A running gag is his tendency to endure the Professor's comically horrific physical abuse, usually in the form of a childish
booby trap or the
rope noose that she uses to walk him.
Teachers ; : : Izumi is a young, constantly flustered, and easily frightened teacher. She is an English teacher, a career adviser, and a school counselor. She tries to enforce the school rules, but is typically unable to accomplish much due to her passivity. Even though she is often nervous and a pushover at school, she is marginally bolder when it comes to her younger brother Makoto, once confronting him about an erotic magazine found in his room. ; : : Manabu is a male teacher who has romantic feelings for Izumi, but is unable to tell her as he thinks too much and is too shy to admit it. These feelings lead him to become the club adviser for the go-soccer club after Makoto bribes him with pictures of his sister. ; : : The Principal is the middle-aged bald principal of Tokisadame High, where part of the story is set. While known for his old jokes and puns, unknown to most, he is a talented wrestler. He is referred to as "Principal Shinonome" implying that he may be the Professor's father or relative, but this was never revealed in the series. ; : : The Vice Principal is known for wearing glasses and a yellow tie. He hates the Principal and doesn't hide the mean things he does to him. He was the previous principal of the school and is incredibly bitter about his demotion, so much so that he began to drink heavily and send daily death curses to the Principal. His constant drinking and stress have utterly destroyed his body, and he describes himself as being one drink away from liver failure at all times. ; : : Kana is a science teacher who is fixated on Nano's robotic nature. She constantly schemes to capture Nano for study, but her machinations invariably backfire, like drinking coffee from the same tranquilizer-spiked jug she had intended for Nano. As such, it is a running joke that she is not there to take classes very often, having fainted from one of her escapades, resulting in many students asking, "Has Ms. Nakamura collapsed again?"
Students ; : : Kōjirō is a flamboyant high school boy who acts like an aristocratic lawyer when in reality his family are just farmers. He likes to ride his goat Kojirō (named after himself) to school and is often seen with his butler. He is very suave and, despite not having many friends, is the object of affection from most girls in the school, yet acts like any other teenage boy, which most girls willfully ignore to preserve their "Prince Charming" mental image of him. Kōjirō used to take kendo lessons with Yoshino, Mio, and Misato, which resulted in the latter two developing feelings for him. ; : : Misato is a peach-haired high school girl who generally acts as a
tsukkomi towards Kōjirō whenever he does anything to annoy her. However, Misato does this by shooting him with various guns and heavy weaponry that
come out of nowhere. In reality, Misato has feelings for Kōjirō, but due to her attitude, she constantly denies her feelings or shoots Kōjirō if he annoys her. ; : : Tsuyoshi is a fifteen-year-old student with simplistic eyes and a natural blonde mohawk which he detests. He wants to be a scientist in the future and thus doesn't believe in the supernatural, but his attempts to disprove supernatural phenomena usually end up with the proof of them being "confirmed", or with embarrassing situations for him. ; : : Haruna is a girl with a large ribbon on her head. She sometimes runs into crazy individuals much to her confusion. She likes to read manga. ; : : Kenzaburō is a brown-haired boy who is the president of the
go-soccer club, which he founded without any knowledge of it being an actual sport. The club eventually became a legitimate team due to a sudden influx of skilled players and has since won the prefectural tournament and was heading to the national championships, but Kenzaburo now wonders why he even stays on the team, as the club has become so far removed from the original intent of it being a place to relax. His rich father is the president of Daiku Industries, which owns many of the businesses visited by the main characters. ; : : Yuria is a quiet girl who is a member of the go-soccer club. She has a crush on Kenzaburō and stays in the club so that he will not be lonely. Like Tsuyoshi, she also has simplistic eyes. ; : : Makoto is Izumi's younger brother, who joins the go-soccer club. He is very skilled at the sport and helps the club grow by bribing Manabu into becoming their advisor with pictures of his sister in her high school years. ; : : Tanaka is a boy who wears a large black afro wig. He is friends with Tsuyoshi. ; : : Weboshī is Misato's green-haired classmate, who has a ponytail. Her real name is not given. ; : : Fe is Misato's orange-haired classmate. She ends her sentences with "fe". Her real name is not given. ; : : Mihoshi is Misato's younger sister and a
kendo student. She envies her senior Yoshino's extreme talent in the sport despite rarely practicing. ; : : Yoshino is Mio's easygoing older sister who goes to college. She likes to wear costumes and often plays pranks on others. She is also Misato and Mihoshi's senior in kendo, a sport she is naturally talented at, but does not practice at the dojo very often. ==Media==