Oni Giri is a signature technique for Roronoa Zoro within his Three Sword Style arsenal in the One Piece series. It was given the name "Oni Giri," which, if looked at in Japanese, contains clever dual meaning and thus adds depth to what the technique can mean. Though basically interpreted as "Demon Slash" or sometimes "Ogre Cutter," it literally means "rice ball.". Typical of Eiichiro Oda's innovations into naming techniques in One Piece, he very often puns or references something cultural to add another layer of meaning to the world-building.
Oni Giri is performed by doing a three-way slash simultaneously by the user. It is attained when Zoro crosses the two hand-held swords across his chest and puts the third in his mouth. In fact, it is not so much the actual attack but rather the stance that gives this technique power and effectiveness. At the moment of attacking, Zoro sends out a mighty cutting force that should overwhelm any opponent with its speed and strength.
The Oni Giri is such an early technique used by Zoro that it has become synonymous with his fighting style. It mostly sees application as an opening attack or as a finisher, which opens its applicability wide in combat situations. Of course, this technique is powerful but not because of the raw power contained within: it's actually hard to block by an opponent because of the three-way slash.
Through the One Piece series, Oni Giri has been evolving with Zoro's raising skills and experiences. Its evolution mirrors that of progress Zoro went through to improve and polish the techniques as a swordsman. The original Oni Giri has spun off into ways to accommodate different situations during combat or be empowered by increased mastery of swordsmanship on the part of Zoro.
One of the more famous variations of the Oni Giri is the "Yaki Oni Giri" (), literally "Burning Ogre Cutter." In this enhanced version, Zoro's swords are engulfed in flames, thereby adding an extra element of destructive power to the already formidable technique. This flaming variant further speaks to how Zoro can adapt his core moves to different situations and opponents.
Another powerful iteration of the technique would be the "Purgatory Oni Giri," which Zoro used during the Wano Country arc. Notably used by Zoro in episode 934 of the anime, this version showed his adaptability, where he combined his Three Sword Style with Hitokiri's kama to execute the attack. Oni Giri: Purgatory is a very nice power-up of the original technique, fitting for the increasingly formidable foes Zoro meets in the New World.
All the recreations of this Oni Giri have been really striking in this anime. For example, episode 934 had a high-quality animated Purgatory Oni Giri sequence where the fans themselves made 4K, 60 FPS versions to show how it's fluidly and stunningly done. These visually-enhanced forms of the technique lent significance to its popularity, further garnering iconic status with these series.
Oni Giri's impact extends outside the manga and anime to many areas of One Piece merchandise and fan culture. For example, notebooks with Zoro have been designed specifically with an "Onigiri Notebooks" label to take advantage of the popularity of the technique and ingenuity of the name. This merchandising displays exactly how intrinsic the Oni Giri has become in the One Piece fandom.
Within the greater scope of the One Piece storyline, Oni Giri has served as a benchmark of sorts for Zoro's growth. From its first appearances early on in the arcs to evolved forms in recent storylines, it has constantly remained a part of Zoro's journey. Much like Zoro himself, the consistent presence and continuous development of this technique carry it from a promising young swordsman to one of the most feared pirates reigning in the New World.