Takashi Hayama (Nijiro Murakami) is a third year high school student. He falls in love with Azusa Oribe (Akari Hayami) at first sight and they begin to date.
One day, Azusa tells Takashi "people who meet me, forget about me several hours later."
Takashi doesn't believe Azusa, but by chance he realizes that he forgot about Azusa. So he won't forget Azusa, Takashi begins to leave a note for himself and Azusa.
Sayaka Kudo (Kasumi Arimura) is a 2nd grade high school student. She is a gal who wears miniskirts and has her hair dyed blonde. Even though she is a high school student, her actual academic grade level is on par with 4th grade elementary school students. During the summer, Sayaka attends a private institution. There, she meets Teacher Tsubota. Besides her mother, Teacher Tsubota is the first adult to praise her. Sayaka begins to change. She studies hard and eventually passes an entrance exam for Keio University.
Naho Takamiya (Tao Tsuchiya) is a 2nd year high school student. During the spring, Naho Takamiya receives a letter sent by herself from 10 years in the future. In the letter, she liked transfer student Kakeru Naruse (Kento Yamazaki). Kakeru Naruse carried emotional scars from his mother's suicide and he died one year later. 26-years-old Naho Takamiya thinks about Kakeru Naruse often.
2nd year high school student Naho Takamiya, with the knowledge of what she feels 10 years in the future, takes action to change her future.
Moritaka Mashiro (Takeru Satoh) doesn't want to follow in the path of his uncle who worked as a manga artist, but ultimately died because of exhaustion. Moritaka Mashiro figures he will graduate from school and work at an office. Things change though when falls in love with a girl at school. The girl, who hopes to become a voice actress, tells Moritaka they can marry, but only after they both achieve their dreams. Moritaka then teams up with fellow classmate Akito Takagi (Ryunosuke Kamiki) to publish their first manga.
A mysterious creature destroys 70% of the moon. The creature then warns that if he is not destroyed by March of next year, Earth will be next. The creature also demands that he becomes the homeroom teacher for 3rd grade E class at Kunugigaoka Junior High School. The government is powerless to say no.
The creature then becomes the homeroom teacher of 3rd grade E class which consists of failed students including Nagisa Shiota (Ryosuke Yamada). The creature is called Teacher Koro.
Meanwhile, the government requests that the students try to kill Teacher Koro even though he possesses super powers. The government offers a 10 billion yen reward for whomever successfully kills him. The students are confused by the situation, but decide to kill Teacher Koro.
When their class begins with Teacher Koro, the students finds themselves having a good time with their new teacher.
Makoto (Kyoko Yoshine) transfers to Omotesando High School in Tokyo from Kagawa Prefecture. Makoto was enthusiastic in the chorus back at her old high school and she looks forwards to joining the well-known chorus at Omotesando High School. Additionally, her prior teacher, Ariake Suzuki (Yuu Shirota), is now an advisor of the chorus at Omotesando High School. He taught her the joys of the chorus.
But, the chorus at Omotesando High School is now in decline and is set to be abolished. Makoto decides to rebuild the chorus.
Tsubame Haruna (Suzu Hirose) is a female high school student. She spends her days peaceful, while concerned about other's facial expressions. She is forced to become the student president. Tsubame Haruna then meets Kei Shizukui (Ryunosuke Kamiki). He has a talented speech writer. With his help, Tsubame Haruna starts a revolution at her corrupt school.
Akiyama Shuntaro, a fourth-year university student who has had a good upbringing because his father is a member of the board of a well-known company, Shuntaro’s employment has somehow or other been determined with those connections and he spends his days aimlessly. Even though he questions his present way of life, he has not taken any constructive action. While on the way to uni one day, Shuntaro hits his head inside the train and loses consciousness, now he can see characters showing train station names in commuters’ heads. Then one day, he happens to see a man without a station name appearing above his head.
Yoshikawa Nao stays behind to live by herself when her parents leave to inherit her grandpa's farm in the country. On the day she moves into her new apartment, she discovers that it was rented also to Uehara Hisashi; a cute, super-cool, popular guy from her school. Not only did their housing agency unexpectedly close down, the landlord of the apartment tells them that they had to pay more for their apartment than they had expected. With no money and no home to return to, Nao and Hisashi decide to live together as flatmates.