"Mishima: A Life in Four Chapters" culminates in the meticulously planned and executed ritual suicide (seppuku) of its protagonist. The entire film is structured as a prelude to this final act, with each chapter and flashback building a psychological and philosophical justification for it. The central twist is not a plot development, but the gradual reveal that Mishima's life and art were a long, elaborate rehearsal for his death. His novels, particularly "Runaway Horses," are shown to be prophetic, with their protagonists committing the very acts of rebellion and suicide that Mishima himself will later perform.
The film's climax intercuts four parallel events: the burning of the Golden Pavilion, the sadomasochistic suicide pact in "Kyoko's House," the seppuku of Isao in "Runaway Horses," and Mishima's own ritual disembowelment on November 25, 1970. After delivering a passionate but ultimately ignored speech to the soldiers at the military headquarters, Mishima returns to the general's office. He then commits seppuku. The film does not show the graphic details of the act itself, instead focusing on Ken Ogata's face and intercutting the act with the sun imagery and the final moments of his fictional characters. This stylistic choice reinforces the idea that this is his final work of art, a moment of transcendent beauty rather than grotesque violence.
A crucial detail revealed at the end is the failure of his second-in-command, Morita, to properly behead him in the ritual (a fact detailed in historical accounts but only alluded to in the film's conclusion as a third member must step in). Schrader's decision to end before this less-than-perfect conclusion preserves the idealized, artistic death that Mishima sought to perform on screen. The hidden meaning that becomes clear is that Mishima never expected his coup to succeed; the entire event was a stage, meticulously set for his public, ritualized death, which he believed would be the ultimate unification of his life, art, and ideals—the perfect harmony of the pen and the sword.