The Cursed Holy Sword

Released in 2004 as the franchise's fifth theatrical film, this ninety-five minute entry hands the spotlight to Zoro rather than Luffy. Directed by Kazuhisa Takenouchi and written by Yoshiyuki Suga, it closes on the song Ano Basho e by Harebare and shipped alongside the comedy short about a pirate baseball match. Its events sit loosely after the Skypiea storyline, since the crew is already aware of their post-Arabasta bounties, and it opens with the Marine commander Drake still chasing the Going Merry from the prior movie.

A prologue shows Asuka Island overrun by pirates a year earlier. A dying warrior named Saga grips a mysterious sword, the Shichiseiken, against the warnings of his fiancee Maya. The blade heals him and lets him butcher the raiders, but it plants an evil presence inside him. In the present the Straw Hats dock at the same island and hear of the legendary weapon, said to be the most beautiful sword on the Grand Line and bound to a curse that, under the red moon, can plunge the world into darkness. Zoro vanishes from the ship after a knife bearing his own name is hurled at him, and the crew is forced to flee a Marine fleet.

Zoro reunites with Saga, now leading Marine swordsmen, and agrees to help him by stealing the three sacred orbs that Maya uses to seal the blade. Sanji and Zoro come to genuine blows, a rarity for the pair, and Zoro cuts him down. Through ancient ruins Robin pieces together the legend: three princes once warred over the sword and a priestess took the accumulated hatred into herself, sacrificing her life so gods could seal the weapon with the orbs. Maya, the priestess's descendant, can perform the ritual that stops the awakening, though some believe only her death will suffice. Luffy and Usopp, meanwhile, stumble through trap-laden caves and recover the orbs.

A flashback reveals that Zoro and Saga trained together as boys and swore to become, respectively, the world's greatest swordsman and the master of a just blade. An accident at sea crippled Saga's arm and washed him to Asuka, where the cursed sword later seized his mind. With the orbs delivered to three towers, Maya raises a barrier, but Saga attacks while she prays. Luffy fights the possessed Saga to a standstill until Zoro arrives and lands the final cut, shattering the curse and freeing his friend. As the crew sails off, Saga vows to honor their old promise.

The film is notable as the only One Piece movie in which Zoro defeats the central villain, and it contains the only serious, non-comedic duel between Zoro and Sanji in the series. It also features some of the most graphic imagery in any One Piece animation, with the opening massacre showing pirates cleaved apart, though the goriest moments are obscured in shadow. Continuity nods abound, including Drake's later remark in the G-8 storyline that he had crossed paths with the Going Merry twice before.