A mother, Nana, and her son, Sato, move to a remote southern island with no relatives. They are stepmother and son, with Sato being her husband Ryoji's stepchild, but the two of them fled to the island to protect Sato from Ryoji's violent behavior. Working hard in the vast sugarcane fields of unfamiliar land, Nana soon catches the eye of a local man, but Sato desperately protects her. Not as a mother, but as a woman... And Nana also begins to accept Sato's feelings, but then Ryoji appears before them...