In the early 17th century, an impoverished samurai named Hanshiro Tsugumo arrives at the estate of the Iyi clan, requesting permission to commit seppuku (ritual suicide) in their courtyard. Suspecting that Hanshiro might be bluffing to gain financial assistance, the clan's senior counselor, Kageyu Saito, recounts the grim story of a fellow samurai, Motome Chijiiwa, who recently made a similar request. Believing Motome was dishonoring samuari code, the clan insisted he follow through with the ritual using his own bamboo sword, resulting in a brutal death. Emphasizing this tale, Saito hopes to deter Hanshiro from proceeding with his request.

Unfazed, Hanshiro insists on going through with the seppuku and begins to recount his own story, gradually revealing his ties to Motome. Through his tale, deep moral and ethical questions about the samurai code and the true meaning of honor are brought to light. As Hanshiro's story unfolds, the extent of the Iyi clan's hypocrisy and cruelty becomes apparent, leading to a suspenseful confrontation between rigid tradition and individual conscience.