At the start of the Edo period, samurai Toyohisa Shimazu is in the midst of a bloody battle against the legendary Tokugawa clan to ensure the successful retreat of the Shimazu clan forces.

After his entire unit is massacred, Toyohisa manages to single-handedly force the enemy to withdraw—at the cost of being mortally wounded. Walking out of the battlefield dejected, he mysteriously finds himself in a white hallway, where he is immediately thrown into a door. He awakens in a different world, and there, he encounters Drifters, other legendary warriors who died and ended up in the same realm. Together, they use the knowledge and experience from their past lives in order to take over an empire and fight against an unknown force of evil that intends to crush all humanity.