「また、必ず会おう」と誰もが言った。

Kazunari Katsuki (Gaku Sano) lied to his classmate that Tokyo stinks. Because of his comment, he goes to Tokyo alone. On his way back, he misses his flight back to Kumamoto. Kazunari only 3,400 yen in his pocket. He becomes confused about his missed flight. At that time, Masami Tanaka (Kaoru Sugita), who works at an airport souvenir shop, talks to Kazunari. On Kazunari's unusual trip back to Kumamoto, he meets many different adults and begins to think about his life.