Prologue: Kurosawa, a witness of the hit-and-run accident that took place near his bar by the Awahi River, gives an account of what he saw. Ten years earlier on a night when the wind and rain of a typhoon raged, Kurosawa had stopped a man from jumping into the swollen river. Just after that, he saw a car hit a young man walking along the river road. The car had knocked the young man down the riverbank and into the water, never to be seen again. Just as Kurosawa was trying to get a look at the face of the driver of the car, a shard of glass from his bar’s window struck his face, blinding one of his eyes. This injury cause a delay in his reporting the hit-and-run accident to the police, Kurosawa recalls during his account.
The scene shifts to the home of Seiko Oride, the mother of the young victim of the hit-and-run, Yuki Oride. Seiko has cancer and has been told by her doctor that she has a life expectancy of about half a year. Together with a freelance journalist named Kimata, she has decided to once again trace the facts related to her son Yuki’s accident and disappearance ten years earlier. As Seiko tells her sister-in-law Eiko of this decision, a disturbed Eiko says she—being a nurse by profession—will accompany them in their search.
Around the same time, a scene takes place at the laundry facility run by Sumisuke Nishida. Sumisuke is inviting one of his employees named Takeo to a Korean barbeque restaurant where a woman he likes is working. Noticing a picture that includes his face on the laundry’s leaflet Sumisuke is holding, an angered Takeo tells him to get rid of the photo and reprint the leaflet. Takeo is the man who tried to kill himself by jumping in the river ten years earlier.
The scene is now Nagoya Station. A man named Oki is here at the station seeing off his pregnant wife Misawo, who is returning to her hometown to give birth. Oki has quit his job at a company that exploits its employees and is now studying to become a certified public accountant. Misawo is trying to convince Oki to come with her to her hometown for the birth. She hands him a Shinkansen ticket, but Oki’s reaction is noncommittal. Oki is the man who was driving the car involved in the hit-and-run accident ten years earlier, and he is still afraid to go back to the town where it happened.
Sumisuke and his group of are heading to the Korean Barbeque restaurant Agashi. Among the group are Takeo’s son Shun and his common-law wife Mei, who is Sumisuke’s younger sister. At Agashi, they are greeted by the easy-going young owner. The hostess Sumisuke has his heart set on, Lala and her fellow hostess Hanako wait on the guests. When Sumisuke starts handing out the laundry leaflet here as well, Takeo gets angry with him again. Shun soon becomes friendly with the hostess Hanako and promises to come to the restaurant again.
Seiko gives an account. The day of the hit-and run accident was the day before her husband, a bank employee, would be moving to the town where he had been re-stationed. It seemed that their son Yuki had gone outside to escape the quarreling of his irritated parents. After the accident, the only thing that had ever been recovered from the river was Yuki’s jacket. Seiko had continued the search for her son, but after being told by the police that they had reached the decision that he must have been swept away by the river, Seiko finally left the town half a year later. She mutters that afterward she kept thinking “on and on” that she could have done more to find her son.
Setting up a working base in the second floor above Kurosawa’s bar, Seiko, the reporter Kimata and the nurse Eiko begin their search for traces of the hit-and-run victim Yuki.
The scene is Takeo’s apartment. With their son Shun’s birthday approaching, Mei says she is preparing a big present.
The scene shifts to the laundry facility. When Sumisuke delivers a new printing of the Agashi leaflet with a photo of Shun replacing that of Takeo, he is disheartened by the news that Lala is going to get married. Pointing out the fact that Lala is an immigrant from China, Takeo says that it is probably a sham marriage just for the purpose of getting her permanent residence status. At that point Hanako enters in everyday clothes; she has come to see Shun.
In the course of her search, Seiko has collapsed and is taken to the hospital. It is the clinic of Misawo’s father. Kimata arrives with news that he has found information about a man with the same name as Yuki and of the same age living in Hachioji. Eiko, says that they should let Seiko rest and she, as Yuki’s aunt, will go to Hachioji instead to see if it is the same Yuki.
The young man who had supplied the information about the man named Yuki turns out to be the young owner of the restaurant Agashi. When Kimata, Eiko and Kurosawa find the restaurant’s young employee who calls himself Yuki, it turns out he is not Seiko’s son. What’s more, the young man tells Eiko that having parents trying to find a lost child for their own purposes is nothing but an unwelcome intrusion for the child. Angered by this statement, Eiko throws a glass of rice wine on the young man. Handing her a copy of the leaflet Sumisuke has made, the young man says he is going to demand payment for the cost of cleaning his clothes she has just covered with wine. Noticing the fact that the leaflet Kurosawa has is the old one with Takeo’s photo on it, Sumisuke exchanges it with a new one reprinted with Shun’s picture.
Takeo comes home and asks Mei what the present she has been planning is. She says that she knows that the records of Takeo’s lineage are false and that she had also learned that Shun was not his real son, so she has made arrangements to have new records created that will make them all legally members of one family.
Misawo [Oki’s wife] is helping Seiko prepare to leave the hospital. When Oki—who has returned to his hometown from Nagoya for his wife’s childbirth—returns to the hospital from shopping and notices the [missing-person] leaflet of Yuki that Seiko has left behind, he suddenly stops cold.
Kimata and Kurosawa are walking along the river. Kurosawa suddenly mentions that he seems to recall the face of someone in the leaflet of the laundry facility.
The scene shifts to the laundry facility after work hours. Mei has made a birthday cake and is looking for Shun, but he is nowhere to be found. Hearing from Sumisuke that Shun and Hanako have gone to the river on a date, Takeo appears to be shaken.
Shun has brought Hanako to Awahi River, where he tells her that he has no memories of his childhood before the age of ten and that the only thing his father would tell him is that he was born at Awahi River.
The scene is Misawo’s family home. With a grim face, Oki is looking at Yuki’s missing-person website. Misawo says that it has been exactly ten years since the accident and that a typhoon will strike this night like it did the night of the accident. At this, Oki confesses to his wife that he was the one who hit Yuki with his car that night.
At Kurosawa’s bar. Kurosawa looks at the old leaflet with the picture of Takeo on it and say that it is the man he stopped from jumping in the river the night of the accident. But, Seiko is looking at the picture of Shun on the new leaflet.
Visit the laundry facility together with Kurosawa, Seiko is questioning Takeo, accusing him of pulling her son out of the river and then taking him off and keeping him as his own son. Takeo rejects her accusation, insisting that Shun is his son and Mei is his mother, and Mei backs his claim. Hearing this, Seiko becomes unsure of herself and leaves exhausted and looking haggard.
Kimata has been sitting in at the bar while Kurosawa is out. In come Misawo and Oki and they ask about the situation. Oki can’t keep himself from muttering that the criminal surely knows that “the time will come” when the truth is revealed. The couple leave the bar just as Seiko and Kurosawa return, but under their umbrellas they don’t notice each other.
At Hanako’s home. Soon after coming to Japan, she had made a sham marriage to get resident status. Having heard Shun’s story, Hanako says she is now ready to talk about her own past. Having shared their stories, the two lie down together.
The scene shifts to the newborn infants ward of the hospital. Misawo started to have labor pains as soon as they left the bar and has now given birth. Oki is overcome with joy at the event. Misawo tells him, “Don’t speak to anyone about the accident. You don’t need to say anything, and it’s best for this new child as well. But, I’ll never let you hold this child again.” With this, she says that she is leaving him.
At the bar. After seeing off Eiko, who is returning home for a short time, Seiko tells Kimata that she has decided to give up on the search for Yuki, and then she says she has “one last request” she wants to ask of him.
When Shun comes home, Takeo finally admits everything. Takeo tells Shun how he had found him and that his real birth name is Yuki Oride, and then he tells Shun to leave their home. Shun runs out. In fact, it has been an act on Takeo’s part to get Shun away from the home for a while, because he has decided to turn himself in to the police.
Takeo’s confession. Ten years ago, after failing in a business venture he had decided to end his life, only to be stopped by Kurosawa. Just after that he rescued Yuki from the river after the hit-and-run accident. With Yuki having lost his memory, Takeo had told the doctor at the hospital that he was the father, after which he had found the will to live as the child came to accept and bond to him as his real father.
Takeo goes off saying that he will spend the rest of his life trying to make reparation for his sins of stealing Yuki’s life and making Shun his personal reason for living.
As her “last request” of Kimata, Seiko got him to find her a bicycle to ride around the area of town near the Awahi River. Finally she says she wants to ride along the river and Kimata’s camera follows her back as she rides off.
Shun and Hanako are walking along the river. In front of them comes Seiko, wobbling precariously on the bicycle as she rides. Just as she reaches the two, Seiko nearly falls, but Shun catches and supports her bicycle.
With a bow of appreciation and nods in return, the three pass each other. Shun walks off, but in the next moment Seiko stops and turns to look back, as if she has finally found everything she had been searching for.