Spring 2001. Yui (Erika Sawajiri), who moved to Tokyo from Hokkaido by herself after the death of her parents, meets Yoichi Kashiwazaki (Naoto Fujiki), a university lecturer, at the bookstore where she works. The two slowly grow closer over time, and when Yui gives birth to a son, Ko (Hiroshi), the two get married.

Hiro (Shunsuke Michieda), the son who was kidnapped nine years ago, is alive. This fact sheds a bright light on the life of Yui (Erika Sawajiri), who had been living alone. Meanwhile, Yoichi (Fujiki Naoto), who has since divorced, has quit his job as a university teacher and is living a reclusive life at his family's Kashiwazaki estate.

Yui (Erika Sawajiri) and Yoichi (Naoto Fujiki) decide to move in with Hiro (Shunsuke Michie). Kino (Yusho Nakajima) says that they can sue Asako (Eiko Koike) in court for not delivering Hiro's presence, but Yui replies that she does not want any more commotion for Hiro's sake. Hiro's birthday party is held at Kashiwazaki Auto, and Rie (Fubuki Jun) is delighted to see him immediately making friends with everyone, and Risako (Itaya Yuka) is also relieved.

Hiro (Shunsuke Michieda) is shocked to find that he has been abandoned after meeting Asako (Eiko Koike) again, and begins to act distant toward Yui (Erika Sawajiri). Yui is perplexed by Hiro's usual cheerful attitude toward Yoichi (Fujiki Naoto) and Rie (Fubuki Jun). Yui realizes that Hiro has not given her any of the school's printed announcements, and that she has not even eaten the lunch she has made for her.

Hiro (Shunsuke Michieda), who is once again living in an institution, has disappeared on his way back. Yui (Erika Sawajiri) is worried that Hiro may have gone to Asako (Eiko Koike), but Kino (Yusho Nakajima) informs her that he found him at an Internet cafe with Imai (Ayumi Mochizuki). Yui is worried and restless, although she decides to trust Kino's words, "Leave it to me. Hiro has learned that Imawei's mother, who has been missing, has been captured on a map on the ...

Asako (Eiko Koike) shows up at Kashiwazaki Auto again and says she is going to work here. Yui (Erika Sawajiri) and Yoichi (Naoto Fujiki) are stunned to learn that Asako was in prison. According to Kino (Yusho Nakajima), the incident Asako committed two years ago was to protect Hiro (Shunsuke Michieda) from a violent man who was following him. Kino tells the truth about the incident that Asako caused.

Yui (Erika Sawajiri) arranges to have dinner with Asako (Eiko Koike) to talk things over. Kino (Yusho Nakajima) is worried about Yui, who wants to understand each other as mothers, but after sending Yoichi (Naoto Fujiki) and Hiro (Shunsuke Michieda) off on a fishing trip, he welcomes Asako home. Asako is told by Rie (Fubuki Jun) how much trouble Yui and her family have been going through, and she apologizes in a low voice.

Yui (Erika Sawajiri) receives a phone call from Asako (Eiko Koike), who says that she and Hiro (Shunsuke Michieda) may be featured in an article. Yui is perplexed when Asako asks her to lie now even if Hiro finds out about the incident two years ago. Meanwhile, Asako learns that Aimi (Nene Otsuka) is trying to approach Kashiwazaki Auto for an interview, and follows her there. However, what she sees is Aimi's son, Ryu (Togan Manaka), who has been abandoned in his room.

Yui (Erika Sawajiri) is shocked to find out that Hiro (Shunsuke Michieda) skipped school to be with a high school girl, Momo (Kaya Kiyohara). Rie (Jun Fubuki) hears about this and says she will hold a family meeting and gathers everyone involved with Hiro at Kashiwazaki Auto.

Asako (Eiko Koike) leaves Tokyo, Yui (Erika Sawajiri) declares to Yoichi (Naoto Fujiki) that she has changed her mind. Hiro (Shunsuke Michieda) is all fired up to prepare for the marathon. Meanwhile, Risako (Yuka Itaya) is unable to tell Taiji (Kazuyuki Asano) and Mayu (Haruka Fujisawa) that she turned down a long-term business trip.