The name of the great swordsman begins in Okehazama.

I transmigrated to Japan's Sengoku period, becoming Mori Shinsuke, a member of the Mabushi rebellion under Oda Nobunaga. Fortunately, I have a built-in system; slaying enemy generals unlocks the ultimate technique. A torrential downpour at Okehazama is taking shelter from Imagawa Yoshimoto. Oda's army launches a frenzied attack, while I silently hold back, waiting to reap the rewards. "Enemy general, Imagawa Yoshimoto, has been slain by me, Mori Shinsuke!" A single slash, head in hand, new technique unlocked! Oda Nobunaga: "Good! From this day forward, you are a member of the Black-Clad Army!" I glanced at my lord, who was only offering empty promises, and weighed the famous sword, Soza Samonji, in my hand. In the chaotic Sengoku period, fame and glory reside only on the edge of my blade.