Keizo Kuno, a man who once lived in the yakuza world, has abandoned his past and now lives quietly, working in a corner of Otaru. Every year, he sends a Christmas present—posing as an “uncle”—to Fumika, the daughter of his former sworn brother, Mitsumura. Fumika is a high school student living a peaceful life, but she suffers from memory loss. As she prepares to graduate in the spring, she longs to ask her so-called uncle one question she can’t let go of: the whereabouts of her mother, whom she barely remembers. Guided by the gift she receives, Fumika travels to Otaru and finds her way to Kuno. Though surprised, Kuno can’t hide his joy. For reasons he cannot reveal, he does not tell her the truth—but Fumika is, in fact, his real daughter. Soon, the grudges Kuno carries from his past ignite violent conflicts in the underworld, drawing the two of them in. Though he cannot call himself her father, Kuno stands up to face his fate, determined to protect his daughter’s future.