A postman learns that he doesn't have much time left to live due to a terminal illness. A devil then appears in front of him and offers to extend his life if he picks something in the world that will disappear. The man thinks about his relationships with ex-friends, ex-lovers, relatives and colleagues who will be sincerely sad when he dies.
Kasumi (Tomoyo Harada) is divorced and lives with her high school student aged son. She supports her family by delivering laundry. One day, she meets Yuri (Takumi Saito). Yuri is a customer of the laundry delivery service. He is a popular designer, known for his designs of cafes and furniture. Yuri talks to Kasumi without restraint. At first, Kasumi is cautious around him, but she becomes attracted to him.
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.
Takeo Goda (Ryohei Suzuki) is a high school student 2 m tall and weighting more than 100 kg. He has a righteous character. The male students adore him, but female students do not like him. All of the girls Takeo likes prefer his handsome friend Makoto Sunakawa (Kentaro Sakaguchi).
One day, Takeo saves female high school student Rinko Yamato (Mei Nagano) from a pervert on train. Takeo falls in love with her at first sight. He feels Rinko likes Makoto, but Makoto isn't the one she likes. Takeo struggles to liaise between Rinko and Makoto.
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.
Yu Akabane (Nana Komatsu) moves to a dormitory room after her father's transfer from work. She is excited that she will live in the same dorm as Takumi Shirakawa (Yudai Chiba) aka "White Prince." Yet, Haruto Kurosaki (Kento Nakajima) aka "Black Devil" kisses her as punishment for going against him. It is Yu Akabane’s first kiss. Since then, she becomes obedient to Haruto Kurosaki.
Erika Shinohara (Fumi Nikaido) is a first year of high school student. While talking to friends, she makes up a story about her "boyfriend." In reality, Erika Shinohara doesn't have a boyfriend. Erika's friends soon begin to doubt her story and Erika is also running out of lies. Erika then sees a pretty boy on the street and takes his picture discreetly. She later shows his picture to her friends as her boyfriend. The boy in the picture is Kyouya Sata (Kento Yamazaki) and happens to attend the same school as Erika. She tells Kyouya about her situation and asks him to be her pretend boyfriend. Even though Kyouya has a pretty appearance, he has a dark side.
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.
High school student Jinta (Nijiro Murakami) is a hikikomori and lives in Chichibu, Saitama Prefecture, Japan. One summer day, when Jinta is absorbed in a video game, a girl suddenly appears in front of him. The girl is Jinta's childhood friend Meiko (Minami Hamabe), but it seems impossible because Meiko died on a summer day. Meiko wears the same white dress when she died, but she looks a little taller. She tells Jinta that she has a wish and that's why she came back as a ghost, but Meiko can't remember what her wish was.
To grant Meiko's wish, Jinta along with his friends Atsumu (Jun Shison), Naruko (Airi Matsui), Chiriko (Marie Iitoyo), Tetsudo (Yuta Takahata) and Meiko gather together for the first time in 7 years. Jinta soon realizes that he is the only one able to see Meiko.