The Diamond Sleeping in the Sea

Kuwazuru Mitsuki is a second year student at Arakawa Nishi High School. One day, her homeroom teacher, Tachibana, suddenly announces the start of the "Letter Game", where every student has to write a letter with his/her true feelings to each of the classmates. However, the "letter" will not include the sender's name. At first, there were a lot of bad jokes and silly "letters", but they slowly accelerate to revealing secrets and confessions, which make everyone question, "Who is the sender?" and "Who will be named next?" This game allows the students to become more aware of each other's hidden worries and thoughts, which slowly deepens the bond among the classmates. Meanwhile, Mitsuki tries to search for the sender of the letter sent to her and she discovers a secret hidden in this "letter game".

Shimako, who works for a travel agency in Tokyo, loves Scandinavia and lives alone in a small apartment surrounded by Scandinavian goods, food, music, and other items that make her feel like she's in Finland. One day, the president of the company where she works suddenly announces the company's bankruptcy, and this leads her to develop feelings for her favorite country, Finland.

When Sendawara Ichika was in the 2nd grade of high school, a doctor told her she only had two years left to live. More than two years has passed since that diagnosis. Sendawara Ichika is now a university student. She spends her days not knowing if this will be her last day. Sendawara Ichika enjoys attending Yurugi Akifumi’s philosophy class. Yurugi Akifumi’s class is popular, but the students don't pay attention to his lectures. Sendawara Ichika though listens attentively. He often talks about the meaning of life and its importance. Sendawara Ichika and Yurugi Akifumi slowly get closer, but Yurugi Akifumi suddenly quits his job at the university and disappears. One day, Sendawara Ichika meets Yurugi Akifumi again and she hopes to continue their relationship, but Yurugi Akifumi tells her something unexpected.

Imai Joji is a detective with zero investigation ability while his daughter, Mei, is a deduction geek. This is the story of a detective who was hanging on the edge of his career but was able to solve a case through his daughter's podcasts.

At Seven Star Town, a high-class facility where Asako works as the head nurse, wealthy elderly people are elegantly living the last chapters of their lives. For Asako, who was living a humble life and taking care of her mother, it was a world far from herself. Satsuki, who works in Seven Star Town, also takes care of her parents who live with her, and her colleague Kuniko also has problems in the family over caring for her father. Asako has problems finding a facility for her mother. Both Satsuki and Kuniko face headwinds in their lives every day. Asako and her friends put into action a bold plan to break the status quo, and the drama of the people gathered in Seven Star Town begins to come alive. Will they be able to find paradise on earth?