Lesson 1: Enter Eikichi Onizuka
Eikichi Onizuka's life is going nowhere. Six years earlier the former biker gang member and his best friend Ryuji Danma left for the bright lights of Tokyo in search of greatness. And losing their virginity. Now 22 years old, Onizuka's in a rut. He's got degree from a fifth-rate college, and still is looking for the job that will net him 8 million yen a year, the ability to rub elbows with celebrities and an unlimited expense account. Needless to say he isn't having a lot of luck with that and ends up spending a lot of his free time peeping up the skirts of girls instead.
A series of lies of increasingly outrageous magnitude made to impress a high-school girl (including trading his sneakers for a BMW) nearly gets him a kiss (and hopefully more) in a love hotel.. only to have the tryst interrupted by her boyfriend: her teacher! After the girl leaps (from the second story) into her teacher's arms, Onizuka decides that his path to greatness will come by becoming a teacher. He gets a haircut and a suit and begins his new journey to greatness as a teacher in training.
Upon arriving at the campus of Musashino Public High School, Onizuka encounters another teacher in training smoking on the school steps. He's been doing the teacher in training gig for a while, and sleeping with dozens of high-school girls in the process! Onizuka is then introduced to his students, the unruly Class O... and is promptly spat in the face by one of them. Though one student, Nanako Mizuki, does seem to be a bright light in the cesspool of a class.
Despite all that Onizuka remains resolved to become a great teacher (and to find the right girl in one of his classes and marry her). On his way home after classes one day he passes Nanako, crying in a park. She had had an argument with her parents and they kicked her out. Tearfully, she asks Onizuka if she can crash at his place. And with tears of joy, Onizuka says yes.
Lesson 3: Hooray For The Sensei!
After hastily trying to remove the layers of garbage and porno mags from the floor of his apartment, Onizuka is ready to play therapist to his upset student. Things move faster that Onizuka could have possibly dreamed as Nanako immediately proceeds to strip down to her underwear and move towards a stunned Onizuka...Which is when he sees the camera flash goes off. Some of the students from Class O have a nice little bit of blackmail planned for their dear teacher. One million yen in one week or the tabloids headlines will read “Teacher-in-Training Caught In Bachelor Pad Biology Lesson.” Nanako cheerfully admits that she'll receive a chunk of the profits and they leave a stunned Onizuka in his apartment.
The blackmailers quickly learn what demon they've awoken however. While celebrating their soon-to-be new wealth in a park, Onizuka and an entire motorcycle gang surround them. After beating up the students and dunking them upside-down in the park pond, Onizuka promises that if their actions cause him to miss out on becoming a teacher, he will make the rest of their lives a living hell.
The next day finds a very reformed Class O dutifully cleaning up the school grounds wanting only for Onizuka to look good so he can become a teacher. The Principal is so pleased by the turn of events that he promises Onizuka a job once his training is over. It's not all clear sailing for Onizuka just yet though. Nanako approaches Onizuka after class and asks him for a ride home on his motorcycle. While suspicious of another setup Onizuka is convinced to help his student out when she tosses her panties onto his head, with the promise of letting him keep them if he gets her home.
Lesson 4: Happiness In A Six-Mat Apartment
After a stressful ride trying to peek up Nanako's skirt in the rear-view mirror the pair arrive at Nanako's luxurious home. Onizuka is in awe of his surroundings, and the giant plate of expensive sushi Nanako's parents had ordered in for her since they would be out that night. Nanako promptly dumps the sushi in the trash and decides that they ought to go to Onizuka's place and she'll make him dinner instead.
Over dinner Nanako talks about how Onizuka's bachelor apartment reminds her of the small, six tatami-mat apartment she used to share with her parents before they had a lot of money, and the fond memories she has of that time in her life. Nanako suggests she stay over at Onizuka's, and all the fun times they could have together before trailing off into silence. Onizuka instead takes her back to her parent's house.
Driving her back home, Onizuka tells Nanako she should be grateful for the luxuries she has and will miss them when they're gone. Nanako again asks if she can stay at Onizuka's and when he refuses she throws herself from his motorcycle, nearly being hit by a truck in the process. In tears, she says she'd rather die than spend another night under her parent's roof. Onizuka concedes to let her stay the night, and ends up sleeping outside the front door in a sleeping bag.
Lesson 5: I Want To Be A Wolf
Three nights pass with Onizuka sleeping outside his apartment. His fellow teacher-in-training who had slept with countless students finds out about the arrangement and encourages Onizuka to be an animal and to do the dirty deed. Nanako returns to Onizuka's apartment that night to find him wearing a wolf costume. Shrugging it off she happily begins to prepare dinner while behind her Onizuka unzips his costume, gets out the cologne and video recorder, and empties out a box of various perverted items onto the bed. Just as Onizuka is about to strike, Nanako begins to reminisce again about the happier times she had with her parents when she was younger and they had less money. She remembers how close they all were as a family, but now with the larger house, they all have their separate rooms and never seem to talk to each other anymore.
Nanako begins to cry, and Onizuka tells her that his apartment is not her apartment from the past, and that she needs to go home. Shocked, Nanako agrees to leave, saying she shouldn't have expected much from a damn teacher, and leaves. Afterwards at Nanako's house, both her parents are home at the same time, something that doesn't happen too often, and begin to argue about work, as Nanako watches television dejectedly in the background.
The doorbell rings, and Onizuka appears in the doorway to make a house call... carrying a sledgehammer.