Young-ho, an Ethnic-Korean living in Japan, decides to close the pachinko parlor that he has operated with his mother Kyung-ja for 50 years along National Route 7 in Akita Prefecture, Japan. When he invites his mother on an overseas trip to celebrate her retirement, she expresses her desire to visit Niigata instead of going abroad. At Niigata Port, Young-ho realizes what this visit meant to his mother, as he recalls how aunt Soon-ja had departed for North Korea from Niigata Port during the mass repatriation project. 　　After his mother passes away, Young-ho, now alone, discovers an old letter from North Korea addressed to his mother. Meanwhile, his daughter Nana, who had been living apart with her Japanese mother following the divorce, comes to visit him. Nana becomes deeply intrigued by the letter from North Korea. Guided by his mother's will, Young-ho embarks on a journey with Nana, driving along South Korea's Route 7 heading northward.