The 17-year-old Yatabe Mineko grew up in a family of seven in a mountain village in northeastern Ibaraki Prefecture. Her father Minoru has gone to Tokyo to work in order to earn extra money. However, her life completely changes when her father does not come back for the New Year. Mineko asks her family to let her go to Tokyo to find him and promises to send money home. In the autumn of 1964, she and two childhood friends Tokiko and Mitsuo are hired to start working at a small factory in Tokyo’s working class neighborhood. After work each day, Mineko searches for her father and gets disheartened at times. Mineko overcomes challenges and starts to lay down roots in Tokyo as she experiences many meetings and farewells amid the laughter and tears with regulars, people of the shopping street, friends, and colleagues. But will she be able to find her father?

Ieji Hisashi, a salaryman who works for a securities company, has a fuzzy memory of the recent five years because of an accident at his job posting. His wife of five years, Megumi and their 4-year-old son seem to wear masks. He can neither tell their facial expressions nor their emotions. He also struggles about his love for them. On the other hand, Ieji feels an attachment to his ex-wife, whom he divorced five years ago, and their daughter. What sort of days did he have in those five years which are a blank to him? Ieji sets out on a journey to find his past self with a mysterious bunch of 10 keys that he has. He becomes aware that he was a cold, career-minded man before the accident, and the persona that is gradually revealed is beyond the imagination of his present kindhearted self.