Anarchy in Japansuke 1999 on netflix

A middle-aged man walks up to young man who is sitting under a tree and shoots him. The film then flashes back to 1981, where a young woman steals a car with a baby strapped inside. She decides to raise the child as her own, and teaches him to shoplift from stores while she works as a prostitute. She strikes up a relationship with a convenience-store clerk, and the two eventually settle down together.