The son's story begins here. Due to home renovations, Shio Yasuhiro and his mother, Shio Yuriko, are temporarily living with his real aunt, Igarashi Shinobu. Tatsumi Igarashi, their cousin who attends university in central Tokyo and normally lives alone, has moved into a room at the house as well. Still, he constantly feels the discomfort of not being in his own home. Yuriko, too, remains deeply aware of being a guest, tirelessly handling all the housework. Watching her closely, Yasuhiro begins to see his mother in a new light—gradually awakening to her as a woman, not just as his mother. As the son of a father who passed away early, he starts to recognize the loneliness and vulnerability in Yuriko's life as a single woman.