As usual, Yankumi was called for her students got involved with cops but this time in a positive way. The 3-D became heroes and for some reason, Yankumi gave so much attention of herself although she didn't participate in the hero thingy. Meanwhile, a proud father was giving so much attention to his son which made him mad and say hurtful words . The father passed away all of a sudden. The boy felt bad and put himself in trouble. On the other hand, while Yankumi is trying to help him, some curious reporters found about her deepest darkest secret...

Some guys are around the neighborhood beating people up and claiming that if they have any problem, they can go to Kurogin high. They also say that they are Hayato and Odagiri. One night the two were set up on a crime they didn't commit and the worst is no one believes them and the police officer wants them arrested. How will Yankumi find the impersonator and clear her students name?

In the first episode, two characters are introduced. Hayato and Odagiri. Hayato is the leader of class and childhood friend of Odagiri. For some reason, Hayato and Odagiri fought and now Odagiri Ryu quit school and is now working to some dangerous guy. Odagiri refuses to go to school as well. How will Yankumi bring back her precious student back to school?

Curious about why Yankumi is so strong despite her looks, Ogata and Kazama's group decides to follow her home, and gets the shock of their lives when they discover who she really is. The cheery atmosphere in their family greatly contrasts Ogata's – his father, a strict teacher from the elite Kaitoku School, is very disappointed with Ogata's status as an Akadou delinquent, and blames his irresponsibility for his parent's divorce!

Yankumi has convinced Ryu to go back to school but Hayato is still against him. The atmosphere in class suddenly changed when the two met. Although Ryu isn't against the reconciliation thing, Hayato still holds grudge of what Ryu did in the past. While Yankumi tries her best to let the two make up, Hayato took Yankumi as an annyoing teacher leading him to challenge her.

Sawada finds Yankumi's lost phone and sets out to return it. In doing so, he ends up in a house filled with Yakuza and learns the truth about Yankumi's family from her grandfather. Meanwhile, the teachers are on the lookout for a violent gang of young men who have been attacking pedestrians, and Kumai has become smitten with a girl from another school, who he learns already has a boyfriend. Later that day, Kumai learns that the girl's boyfriend is the gang's next target. Concerned for her safety, Kumai rushes after them. While he is watching, the gang members corner the girl and her boyfriend, and the boyfriend runs off. What will Kumai do?

Yankumi talks to her students’ parents about their future during PTC, one of them being Honjo Kengo's dad, a tofu store owner. When he collapses from over-fatigue, class 3-D fears that Honjo will have to drop out, so they decide to raise money to help him out by trying out different jobs. Honjo, on the other hand, encounters an old senpai of his, Narita, who lends him the money he needs – but with serious consequences.

After few days, the class 3-D will be graduating but problems occurred when Kudou came. The class 3-D promised not to fight till graduation but when Kudou's gang attacked them... On the other hand, the chairman is determined to kick out Yankumi together with her 3-D. What will Yankumi do?...

The story line in this episode is Odagiri and his father. The father of Odagiri is a high ranked police which is the opposite of Yankumis grandfather. The father is against the friends of Odagiri and locked him up but his friends helped him break out. How will Yankumi helped her student when her family is in the line?

Kuma's shop (previous student form season 1) is being threatened by some bad guys but refused to tell Yankumi but did seek help from Hayato. He figured out that since he graduated, he is no longer a student of Yankumi so he can't just ran to her every time things gets bad for him. On the other hand, the family of Hayato will be introduced and where in the world did he get his jerky attitude.

The Spring Inter-Class Competition is nearing, and now that Ogata's and Kazama's sides have already made peace, Yankumi is more fired-up to have the whole class join and conquer the rugby match. Ichimura "Ichi" Rikiya, Yankumi's student, meets an old classmate from junior high, Takasugi, who seems to be a quiet, studious boy, but actually has a dangerous side to him.

A serial purse-snatcher is targeting women in the neighborhood near Shirokin High School, and Uchiyama, one of the students in Class 3-D, is a prime suspect. Determined to prove Uchiyama's innocence, Yankumi and a few of her students set out to catch the real thief.

It's time for Shirokin High School's annual sports tournament, and the initially reluctant students of class 3-D have been goaded into participation by dismissive remarks from the head teacher, but they need one more student to field a basketball team. Incidentally, Yankumi has discovered that there's another student in the class, Yuki, who never shows up and she never even knew existed. But Yuki, who left because of bullying by Minami and Kumai, shows no interest in going back to school. Can he be convinced to return and face his fears?

When the students create posters making fun of her and the head teacher, Yamaguchi learns that they have given her a nickname, "Yankumi", which she unexpectedly embraces. One of the students, Minami, is seeing a new girl. One day, he arrives badly beaten and gets into a fight with another student, Sawada. It turns out that the girl Minami is seeing was also going out with a boy from another school, who calls him out on the matter. Inspired by her grandfather's yakuza values, Yamaguchi encourages the boys to stick up for their friend.

Yamaguchi's fellow teacher Shizuka, who teaches English, is also working nights at a club in the Ginza district. One of Shizuka's students, Noda, who has developed a crush on her, gives her a necklace, and later follows her to the club, where he sees her throw away his gift. The enraged Noda posts pictures online, exposing Shizuka's second job to the principal, who threatens to fire her. After a talking-to from Yamaguchi, the principal promises not to fire Shizuka if all of the 3-D students can earn at least 30 points on their English midterms. Yamaguchi gets to work preparing after-school study sessions for the students, but will it be enough to save Shizuka's job?

Because of Shin's scary story, Yankumi is scared to walk alone to the school hallway. One time she left her phone and thinks that someone was following her only to find out that it was a little boy. The boy was Yuta Nakashima-sensei's step son. The boy think of the Nakashima as her mom but since they aren't blood related, Nakashima thinks they are not. How will Yankumi give Nakashima her senses?

Three years after her resignation from Kurogin Academy, Yankumi returns as the new homeroom teacher of Akadou Academy's 3-D! Upon her arrival, she discovers that the class is full of delinquents, and is divided into two opposing groups that are always at each other's throats. One of the students, Kazama Ren, is suspected to be behind a series of muggings, and while the rest of the class doesn’t seem to care about his predicament, Yankumi resolves to prove Kazama's innocence.

Determined to teach class 3-D the true meaning of comradeship, Yankumi seeks out different ways to relate and get closer to the students, yet all her efforts seem to be thwarted. Meanwhile, the two heads of said groups, Ogata Yamato and Kazama Ren, decide to have a one-on-one fight to finally determine who's the better boss, but when this turns out futile, they find themselves settling their differences in the most unusual of means.

Yankumi, the teachers and class 3-D meet Kaoruko, Kazama's older sister. She visits Akadou Academy, and chastises Kazama upon finding out that he has a part-time job, which is prohibited in school. Amidst the "Springtime Eliminate Delinquency Campaign" organized by Sawatari, Kazama faces the possibility of expulsion for deliberately hitting a police officer, causing him to have a falling out with his sister.

Class 3-D is planning a hook-up party with some girls from the neighboring schools, but Kuraki "Kura" Satoru is indifferent... for he is actually in love with Saki, a sickly girl he met a week prior. Wanting to take a break from the confines of the hospital, she calls Kuraki, and the two go out to have fun, until Saki's disease kicks in. This enrages her parents, and they file a complaint to Sawatari, prohibiting Kuraki from ever seeing Saki again. Unable to bear her student's misery, Yankumi steps in to help.