The original work is based on the manga of the same name by Aoi Hiiragi, which was adapted into an animated film by Ghibli. This film adds subsequent original plots based on the original work. Although the film is an original story, it faithfully reproduces the world view of the original work and tells the story of "Shizuku" and "Seiji" who have become adults 10 years after the story in the original work. After 10 years, Shizuku (played by Nana Seino), who dreamed of becoming a novelist, became a children's novel editor at a publishing house. She gave up her dream and began to drift apart from Seiji (played by Tori Matsuzaka), who continued to pursue his dream overseas. Shizuku began to work hard to find the original intention of the two to encourage each other and move forward together.