The year is 1458. A child is born in the village of Otsuka, in Musashi Province. His name is Shino Inuzuka. After coming of age, he is entrusted with a legendary sword, the Murasame, by his father Bansaku. Shino's father, however, commits hara-kiri after losing face when his brother-in-law, Hikiroku Otsuka, tries to trick him into giving up the sword, Then Shino, devastated by his father's death, somehow comes into possession of a small bead, On this strange bead, the Chinese character ""KO"", symbolizing filial devotion mysteriously appears.