In 1535, Obayashi Kansuke, a masterless samurai, is on his way home to succeed his adoptive father after 15 years of journey studying military strategies. At a deserted village he drops in at, he saves a girl from a samurai. The samurai is one of the soldiers under Takeda Nobutora, the warlord of Kai, who are in the battle with the Imagawa clan of Suruga. The girl named Mitsu falls in love with Kansuke. Meanwhile, the Hojo family of Sagami invades the domain of Kai. Kansuke goes to watch the battle between the Takeda and Hojo armies. Though Kansuke has stopped her, Mitsu follows him and is caught by the soldier of the Takeda clan again.