Club Introductions Arc Edit
The first chapter of Oresama Teacher begins with Mafuyu explaining that due to moving schools, she must live alone and cook for herself for the first time. She takes one bite of her instant noodles but immediately spits it out in disgust. As she wonders what she did wrong, each of her attempts prove fruitless and she gets the same disastrous results each time. Ultimately, she sighs in defeat and decides to buy something. Her new unform catches her eye and Mafuyu stares at it in admiration temptedly and ends up wearing it to the store.
After buying her things, she excitedly imagines her first day as a high school girl but her thoughts are interrupted by a loud noise, accompanied by some threats. Mafuyu watches from afar and is surprised to see the man smiling despite being hit in the face by some other men. She laments on whether to intervene and stop the fight and reflects on why she had to move in the first place.
In a flashback, Mafuyu explains that she had been a tomboy and female delinquent. After she defeated the last person, her followers rejoiced and cheered for her victory. They then threw her an extravagant celebration, the "Congratulations, Mafuyu-san Club" to celebrate the unification of the Saitama Prefecture. Kangawa Kouhei and Maizono Yuto were among them. However, a policeman showed up and her 'loyal' followers fled the scene with zero hesitation and left her to be caught by the man with no chance of escape.
At the news of her daughter's arrest and expulsion, Mafuyu's mother was outraged. She made Mafuyu give up her lifestyle to be a normal student in Midori Ga Oka Academy. The school allowed anyone to enter as long as they paid the fee and had a reputation for its delinquency, so even Mafuyu could enter. The dormitories were full, however, which meant that she would have to live alone. Mafuyu's mother threatened to disown her if she got into another fight.
She kicks and throws her bag at one of the men when she sees him pull out a knife, which she calls unfair. As she tries to leave, Takaomi holds her up from behind, commenting on her light weight and asks about what sports she does. He thanks her from intervening and she finds out that he 'goes' to Midori Ga Oka.
Takaomi's Bet Arc Edit
Three Day Holiday Edit
Mafuyu spends her first day of the holiday in the town near the academy. Throughout the day, she hears people speaking of the feared delinquent 'Mahfuyu', and wonders just who it may be. When she heads back to Strawberry Heights, she sees the man who began the Mahfuyu rumour, the number two of Higashi, Maizono Yuto.
On the second day, Takaomi forces her to go the beach with him. She notices that he lacks the usual mean smile, and he annoyedly tells her of the angelic duties teachers have to do. Maufuyu sees that he appears the same as he did in his high-school days.
Takaomi says that they should buy swimsuits, and takes Mafuyu to a swimwear store, where she looks at all of the bikinis in shock. Takaomi suggests that she should buy a peculiarity perverted looking two-piece, though Mafuyu backs away from the teacher. He then shows her a stringed bikini, and she proceeds to pull one of the strings, making the swimwear loose. Takaomi laughs and says that he did the same thing in junior high, only to his girlfriend rather than a mannequin.
Ayabe Arc Edit
After Ayabe Reito tells her the story of his life one year prior to the story, she forces him to take her to his home. Though he refuses, Kyoutaro Okegawa hears the two debating while on a stroll, and angrily chases Reito (believing that he wished to marry Mafuyu) to the Student Council room, with Mafuyu after him. Mafuyu then receives the address of Reito's parent's house from Miyabi, and goes with Reito to his home by train.
When they arrive at the stop, Ayabe insists that he stays at the train station, so Mafuyu threatens to tell Ayabe's family that they are engaged. Reito hurriedly joins up with her, and they see Reito's younger brother, Umestegu Ayabe. Mafuyu approaches Umestegu, though does so with confusion, and ends up speaking to him like a delinquent. After giving him some food, Mafuyu hurries back to Reito, where they discuss Umestegu and his habits of taking food from strangers. They then spot Ichika, Reito's eldest sister, and watch her force her 'curler' to curl her hair in a amazement.
At the end of the day, Mafuyu and Reito sit together, with Reito thanking her for going with him. He smiles and speaks about how he was worried that they were doing badly without him, but was glad that they hadn't changed at all. Mafuyu comments that he didn't really like being alone, and that no-one wanted him to be bored at school. Shen then sees a small girl attempting to lug along a large bag of groceries, and Reito recognizes her as another member of his family, Ayabe Kozue. After a touching reunion of the Ayabe family together, Mafuyu joins Reito and his family for dinner.
Art of the Echo Arc Edit
Hayasaka leads a club meeting and concludes that they must get on the offense to attack the student council. All the present members (i.e. Yui, Aki and Mafuyu) object. Mafuyu explains that while she appreciates his enthusiasm, she has been suffering from muscle pains ever since the school trip; Aki thinks they'll lose and he'll be left without protection; and Yui voted with the majority. Mafuyu asks why Hayasaka suddenly wants to do this and he explains that they've been able to defend against the student council's movements so far, but in the end, the club has close to none info about them. For example, why have they been coming one at a time?
Mafuyu thinks about what she'd do if she were the president, and notes she would definitely not make the student council move separately in the way they have been doing. Mafuyu asks Takaomi if his bet with the chairman had a condition like that. She is surprised when he says that's not the case. Takaomi clarifies that the bet originally had nothing to do with Miyabi, so there was no reason to make this kind of rule. If the student council is moving according to rules, those rules were made by Miyabi alone. As she thinks about that, Mafuyu asks Takaomi what he would do if he were the president and after hearing his ruthless plan, she comments that she is not his enemy.
Lost in her thoughts, Mafuyu unconsciously goes to the student council room and finds out that nobody is there when she peeks though the door. She hears footsteps and takes refuge inside but hears the footsteps getting closer and she hides behind cardboard boxes. The person turns out to be Momochi Runa. Mafuyu's muscle pains unluckily kick in when she resolves to run as soon as Momochi turns her back. More of the student council members enter and Mafuyu panics when she hears somebody coming.