Takeshi Hashimoto, on the brink of turning 30, struggles with insomnia. He finds himself repeatedly dreaming the same dream. Despite seeming to have a successful career and personal life, Takeshi feels stifled and stuck in his current existence. When his close friend and colleague, Saeki, offers him some advice, Takeshi decides to try changing his approach to life. However, the next day, Saeki suddenly takes his own life, leaving Takeshi even more bewildered. Out of the blue, a girl named Sai and a mysterious man named Hōsaku—whom Sai calls her brother—appear in Takeshi's life. Their natural and intriguing presence helps Takeshi slowly reconnect with himself. One day, after receiving a promotion offer, Takeshi decides to turn it down after much thought. “I want to change the way I’m working…” he says. As he begins to notice small changes within himself, he starts to forge his own path.