Amawa Hibiki is a young man just out of college, with an education to be an athletics teacher. He's been having a hard time finding a job since he graduated, so all his money has gone towards living expenses. When his landlady demands his first payment to live in her living establishment upfront, he heads to the local middle school to get hired as a teacher. However, the principal refuses to hire him without hesitation. She will not hire men as teachers and makes it clear that she hates all men, saying they put no love into their passions and work. Amawa does not give up and with the help of his landlady, he crossdresses as a woman without a second thought, and gets hired, so he can earn money and also prove the principal wrong. Now, he has to keep his real gender a secret, and avoid strange situations, including the affections of his students (from both genders).
Hibiki Amawa is an entusiastic young college graduate who wants to be an athletics teacher, he doesn't have a job but needs to pay for his living fees which he can't pay on time. When he moves to Lulu Sanjo's establishment he is unable to pay. So he goes to Seito Sannomiya Private School to become an athletics teacher. However the principle doesn't think that men can't love and so couldn't teach. His landlady disguises him as a woman, because he wants to prove her wrong. He uses a voice transformer and gets through, to get the job he has to prove that he is a good teacher. After Fuko Kuzuha runs for the first time without tripping over he gets hired. However he ends up having to sort out fights and do things he wouldn't do as a man, and keeps almost exposing his identity. The Riko Mukogawa, the principles deputy, has a strong suspicion of him being male and keeps trying to prove it. To keep his identity secret he has to pull alot of stunts. A man starts to appear in the girls dormitories so Hibiki ends up being assigned to live with them to his distress. Hibiki changes the long skirts the girls have to wear and introduces burumas to make it easier for the girls to excersice. During parents weekend it is Hibiki's turn to do preform, he asks the parents to do the long distance run with the children so that they can develop stronger relationships. However Fuko's mother died and her father is travelling on business, her mothers picture got dropped in a river earlier so she is alone. To her delight Hibiki steps in and cheers her up. During a scheduled physical examination of the students, Hibiki is told to take one too. Luckily he gets away with it because Lulu turns out to be the examiner but it is a close call otherwise. Hibiki discovers he is picking up female characteristics. But he has no time to worry about it as a fight starts between his class and he has to find out why it started. The schools directer decides that Hibiki should marry his nephew, the students find out and spy on the poor nephew. But no one knows Hibiki is a man! Luckily a chance encounter between the male Hibiki and the nephew happens when he hits Hibiki with his car accidently. So Hibiki discovers that the nephew already has someone he loves and convinces him to tell his uncle. Days later Shiro Naruo is accused of stealing Reiko Mukogawa's salary. She saw him exit the teachers lounge, but Hibiki stands up for him because he sent him there to pick up his grade book as Hibiki forgot it. The male students are forced to clean the school where as the girls don't. They fight againt the school because they have less rights. The also threaten the safety of a priceless statue. It turns out Shiro Naruo didn't steal the salary but hid it among some papers on Reiko's desk. Unfortunantely it turns out he hid it in the papers which were subjected and have been burned as trash. Hibiki makes up for it by borrowing money and giving up her salary. Hibiki's class goes on a camping trip were affections come out. Hibiki turns out to have an admirer too. A problem occurs when a male and female student are left alone in the rain and take shelter elsewhere. Reiko doesn't believe their innocence and teaches sex education instead of the rest of the trip. They turn out innocent. Fuko gets confused and worries about her feelings for Hibiki who she believes is a girl. She goes missing and everyone looks for her. Hibiki believing she's been kidnapped tries to save her from a fortune teller but the stall burns down. Hibiki is injured and is sent to a hospital. Reiko Mokogawa photographs Hibiki's transformation and almost kiss with Fuko. She exposes his identity and tries to promote an all girls school. Hibiki departs the school but Lulu makes the children realise something important and they all go to stop her but too late. They happily waved goodbye in the end. It is hinted that Lulu is a man and was the last male teacher at the school. It also is hinted that Akira Fukae is starting to accept Fujio Himejima as a friend.
Hibiki Amawa is a typical optimistic college graduate whose goal is to become a professional school teacher. Hibiki is in fact a very competent and focused young man who proves that, man or woman, he is proficiently capable of teaching fitness and counseling.
Lulu Sanjo is the landlady of the Gochiso apartments and school store owner in the same establishment. Despite her incredibly short height and age, Lulu is a very able individual; powerfully skilled in mechanics and technology. Hibiki's strong determination leads her to offer him a plethora of assistance, and with it he is able to aesthetically change his sex and maintain the disguise throughout his time on campus.
Clumsy yet selfless, Fuko Kuzuha is a student at the Seito Sannomiya Private School. Despite being accident prone and easily flustered, Fuko is a very strong willed girl who enjoys motivation and interpersonal satisfaction; even at the expense of her own time and dignity. Much to her own personal anxiety, she takes a tender interest in Hibiki's drag, which develops into gender confusion and shame; but eventually confident attraction. Her mother died when she was six years old and her father is a unmarried traveling businessman. Fuko resides at the school dormitories.
Mori Koji is a salaryman who is a tenant at the Gochiso apartments; room 101. He has a peculiar fascination with photographing schoolgirls' uniforms with his camera and unusually large mirror; frequently strapped on his back. He is good friends with Tofu Tofukuji.
Tofu Tofukuji is a retried elderly man lodging at the Gochiso apartments; room 201. He harbors an obsessive hebephilic interest in Fuko Kuzuha, shown by his photograph collection littered on his apartment walls. A harmless, kind-hearted pervert, Tofukuji is often willing to sacrifice his own safety and freedom to help Hibiki; or otherwise satisfy his craving for upskirts. He is good friends with Mori Koji.
Hibiki's pet dog. Lulu ends up using Kura Ge as motivational collateral for the unpaid rent. While the breed of Kura Ge is never mentioned, he seems to resemble a Bichon. Kura Ge can usually be seen with a wooden sign hung around his neck that read feeble pointers or, more often than not, comedic statements.
Chieko Sannomiya is the eponymous principal of the Seito Sannomiya Private School. She was appointed office a decade prior to the story and carries herself in a conceited, yet formal, aristocratic manner. As a radical misandric, Sannomiya heavily supports feminism and irrationally views males as barbaric nonentities who have no positive qualities. At the conclusion of the series it is revealed that an incident between a man and her lead to her sexist ideology.
Vice-principal of the Seito Sannomiya Private School. She works closely with Chieko Sannomiya, and like her, is a stern misandric; resulting from a failed marriage. Mukogawa grows the most suspicious of Hibiki early into his career and tries debunking his identity several times. She has one child who is never mentioned to both the staff or students of the institution.
A somewhat aggressive tomboy, Fujio Himejima is a student at the school. She wears her hair in two loose pigtails, tied by her signature green bows. She has a black belt in Aikido and develops a crush on fellow student Akira Fukae, who unfortunately, does not reciprocate. Fujio resides in the dormitories.
Miho Umeda is a student at the school and is Fujio's closest friend. Her maturity is considerably more developed than her friends and this at times makes her behave in an arrogant manner; especially when it comes to her past and current experiences with boys. As a result, the other girls tend to look up to her and this prompts her to act like a role model for them. Miho resides in the dormitories. She is a foil to Seiko Kasuganomichi.
Seiko Kasuganomichi is a fairly quiet student. Her family is wealthy and she is often seen as being sheltered. She is well known for getting uncomfortable, in some cases fainting, at the sight of naked men; photographic or physical. Fujio resides in the dormitories. She is a foil to Miho Umeda.
Quiet and composed, Akira Fukae is one of the primary male students on campus. Even though he usually tends to be level-headed, Akira is not afraid to speak his mind or take a stand for what he believes he is fair and just. His father is a private investigator. He occasionally teases Fuko Kuzuha in a rude and hostile way, but despite this, he harbors a strong crush on her.
Kyosuki Aoki is another one of the few male students at the school, arguably the most energetic and is also the tallest; comparable to Miho Umeda to the girls. He is takes the biggest interest in Hibiki's drag and frequently proclaims it to her and the others. Is good friends with Akira Fukae.
Another enrolled male student at the school and a close friend of Kyosuke Aoki. He is the most lecherous of the group.
Another of the few male students. He is a gentle and quiet boy, who in episode nine is unjustly accused of stealing Reiko Mukogawa's salary when he is asked by Hibiki to visit the teacher's lounge and retrieve his grade book.