Yoru is one of the strongest swords in the world, ranked as one of the 12 Supreme Grade swords. It is a "Black Blade" (黒刀 Kokutō?) that is currently owned by Dracule Mihawk, the "Strongest Swordsman in the World".
A Western-looking sword, Yoru is a cruciform and well-ornated weapon with a curved, single-edged, black blade—resembling an oversized kriegsmesser. It has a total length of well over two meters (being over a head taller than Mihawk, who stands at 198 cm, when placed on his back). While not in use, due to lacking a scabbard, Yoru is held upside-down against Mihawk's back by two simple holding loops integrated into the man's coat.
Yoru's hilt is more than suitable for two-handed use at almost half the blade's length (though its length portrayal is inconsistent). The bandage-wrapped grip (white in the manga, grayish in the anime) has on its top a large and round cabochon of red (blue in the anime) color to serve as the pommel, being set into a circular, golden mount. The golden crossguard is extremely long to the sides, such that on Mihawk's back, especially seen from the front, the sword resembles a crucifix. In particular, the guard constitutes a thick, continuous bar perfectly right-angled to the blade, flat on all sides with a rectangular cross-section, but on each end being forked; recurved up and down like a cross moline. Centrally along the front and back sides of the guard are rectangular grooves filled with a swirly sprig relief for detail. The groove on each side is broken in the middle where a rather large, red cabochon is set in (topped by a smaller variant of itself); on each forked terminal of the guard, again on both sides, are more such red stones, this time in trios (from the outer to the inner ones decreasing in size). In the anime, the stones are different: three smaller, blue ones adorning the center (plus a yet smaller one topping the middle), with in-between pairs of smaller, green gems, and on the ends of the arms two unequal-sized stones, the outer and inner ones respectively blue and green (and divided by singular, once again smaller gems colored purple). Otherwise, about 1/3 down each flat of the blade, centrally from the crossguard, are langets, edged the same as the crossarms.
The blade is jet-black (as played on by the sword's name, meaning "Night") with a perfect, mirror-polished finish and an extremely sharp edge. A strong sheen (greenish in the anime) is aslant the blade, visible at intervals; in the anime, the temper is described as an "irregular double-clove pattern" (乱刃・重花丁字 midareba: jūka chōji?). In shape, the blade possesses a mild, gradual widening in profile until its top-third section, whence it tapers to a sharp point and, with its flat back, curves upward, with a distal taper toward the tip.
|— Dracule Mihawk on Yoru.|
Through Mihawk's unparalleled swordsmanship, Yoru yields immense power, with its owner easily cleaving asunder large structures, from a war galleon to an enormous mountain of ice, with merely single swipes of the blade. His swings unleash incredibly potent, compressed airwaves (in the anime appearing as light-greenish energy waves) that can travel long distances while retaining their slicing power, even hundreds of meters away. Yet while potentially carrying such phenomenal force, Yoru is also gentle, enough for Mihawk to deflect the course of bullets aimed at him with but a slight touch of the blade and to send out incredibly accurate, well-placed "flying slashes" that can present a menace from any distance. The aforementioned is despite Yoru's great weight, inferable from its formidable size, as Mihawk brandishes the sword effortlessly with both one and two hands, as though it was a mere extension of his arms.
Although Mihawk does not name any of his attacks in the mainstream of the series, there are several specific moves he has used during it that are named in various video games. Below is a description of the variety of attacks shown.
- Kokuto Issen (黒刀一閃 Kokutō Issen?, literally meaning "Black Blade Brandish/One Flash"): Mihawk swings his blade to launch an invisible flying slash able to cut everything in its path, making for an extremely strong, far-reaching slice. A vertical version of this attack was first seen to cut Don Krieg's galleon in half crosswise, and a horizontal version was seen much later during the Summit War, in Mihawk's attempt to hit Monkey D. Luffy, but missed, instead slicing apart a faraway, mountainously big, frozen tsunami lengthwise. This attack is unnamed in the manga and anime, named only in Gigant Battle.
- Mihawk swings Yoru down in front of him, thereby launching a massive, far-travelling slash wave foward, able to cut rapidly through a massive ice sheet and supposedly much more. Mihawk was seen using the move to attempt to strike Whitebeard, but "Diamond" Jozu was able, in the manga, to halt and with his body dissipate the attack; in the anime, the slash wave forced the diamond-bodied pirate back a distance, having him struggle for a brief while and yell from the effort while ultimately only diverting the wave upward, rather than outright cancel it, causing it to dissipate on its own. It is unclear if Jozu blocking the attack was possible because Mihawk lacks the ability to cut diamond, because he did not expect Jozu blocking the attack (and thus did not waste the energy to send a slash strong enough to cut diamond), or because of an issue involving Haki, but Jozu was unharmed by the endeavor. Regardless, while a simple motion, the attack is extremely powerful with an immense range. Because a marine called it "The World's Strongest Slash" (世界一の斬撃 Sekaiichi no Zangeki?) when it was used, it may be mistakenly thought to be Mihawk's strongest offense. Contextually however, an accurate translation shows that the marine simply meant it was a slash made by the world's strongest swordsman. Mihawk himself noted, before performing it, that he merely wished to "measure the distance" between him and Whitebeard (i.e. test their gap in strength), suggesting that he did not put his full power into the slash.
- Chi o Hau Zangeki (地を這う斬撃 Earth-Crawling Slash Attack?): Mihawk swings Yoru downward, generating a rapidly forward-travelling slash wave that (as the move's name suggests) trails the ground; in the manga, it is notably more spiraling in shape, akin to Roronoa Zoro's Sanjuroku Pound Ho. With Mihawk's outstanding eyesight, it becomes an incredibly precise attack, able to tag a Gear Second-using Luffy mid-motion and from fairly far off, in the midst of a disorderly battlefront without hitting any of the multiple in-between combatants. First seen being used against Luffy, it is unnamed in the manga and anime, named only in Gigant Battle.
- Kokuto Arahoshi (黒刀荒星 Kokutō Arahoshi?, literally meaning "Black Blade Savage Star"): Mihawk jumps up high into the air, standing with both his feet on the crossarms of his sword, and descends swiftly to impale his opponent from above. It was first seen being used against Luffy, barely missing. While unnamed in the manga and anime, the attack is named in Gigant Battle. Additionally, a variant of it is part of Mihawk's moveset in Pirate Warriors.
- Kokuto Saku (黒刀朔 Kokutō Saku?, literally meaning "Black Blade First Day"): A counterattack. Mihawk awaits his opponent's next move while holding his Black Blade with two hands over his back. Once the enemy does attack, Mihawk counters extremely swiftly with a forceful downward slash. It was first seen attempted to be used against Luffy's extremely fast Gomu Gomu no Jet Bazooka, but Luffy, having a premonition of his arms being cut off, redirected his punches to the ground, giving Mihawk no chance to commit to his slice. The attack is unnamed in the manga and anime, named only in Gigant Battle.
- Kokuto Kogetsu (黒刀弧月 Kokutō Kogetsu?, literally meaning "Black Blade Arc Moon"): Mihawk swipes Yoru erratically at great speed, successively producing multiple mid-sized cutting waves to hit opposition from short-to-medium range. The attack was first seen used against Luffy, who had trouble dodging it. Remaining unnamed in the manga and anime, this attack is named only in Unlimited Adventure, Unlimited Cruise, and Gigant Battle.
Video Game-Only Techniques
- Kokuto "Samidare" (黒刀「斬乱」 Kokutō "Samidare"?, literally meaning "Black Blade: Slash Riot'"): Mihawk performs a chain of slices forward, finishing with a black flying slash. The attack is used in the Pirate Warriors games, where it is localized as Black Blade: Wild Slash.
- Kokuto "Mu" (黒刀「無」 Kokutō "Mu"?, literally meaning "Black Blade: 'Nothingness'"): The area is blanketed in darkness, and Mihawk strikes his enemies with swiftly executed slices, cutting them down over a wide forward range. This attack is used in the Pirate Warriors games, localized as Black Blade: The Void.
Anime and Manga Differences
As noted in the Appearance section, the cabochons on Yoru's hilt are red in the manga, while in the anime they are blue, green, and purple. Also, in the anime and video games, Yoru's blade is quite wide while, in the manga, it is portrayed as comparatively slenderer. The latter seems to have changed in the anime around Episode 489, since when the sword appears thinner like its manga counterpart, including episodes post-timeskip.
Notably in the anime, during the Marineford Arc when Mihawk first prepared to enter the battle, Tashigi, in observing Mihawk's sword, offered a description of it, stating that the temper of its black blade is an irregular "jūka chōji" (double-clove) pattern; a type of temper line or "hamon" found on Japanese swords. It should be noted that, not only does this description not occur in the manga, a double-clove pattern is not readily discernable in either the anime or the manga the way Yoru's blade is depicted.
Otherwise, a difference noticeable in the anime is that the blade of the sword emits purple streaks when swung during its first use against Zoro, which much later, during the Marineford Arc, changes to the color green, as portrayed by Mihawk brandishing Yoru and the various flying slashes he sends out with it.
- In Episode 515 (anime-only), Mihawk has Zoro battle a humandrill wielding a sword near-identical to Yoru, the only differences being the light-silver blade as opposed to black, and red cabochons adorning the guard (as opposed to the anime-specific blue/green).
- For the 4Kids adaption of the anime, the sword's crossguard was significantly shortened because it too much resembled a crucifix.
- In Volume 95's SBS, Oda drew a joke rendering of Yoru, alongside Mihawk's Kogatana, personified as humans. Yoru took the form of a "cool older sister" with dark hair in twintails, wearing a skirt.