Kamikaze (カミカゼ, Kamikaze), better known by his hero alias Atomic Samurai (アトミック侍, Atomikku Zamurai), is the S-Class Rank 4 professional hero of the Hero Association and is recognized as one of its most powerful heroes. He is a swordmaster and a member of the Council of Swordmasters.
Atomic Samurai has long black hair tied in a ponytail. He has dark eyes and a defined jawline. He sports a small goatee and is usually seen chewing on a blade of grass. His attire consists of a hooded red cloak with an atom symbol on the back draped over his open black haori. Beneath the haori is a traditional loose-fitting white robe tied with a white sash and two haori himos. He wears his swords on his left side.
Atomic Samurai has a rather prideful and jocular personality, as seen when he refused to shake Saitama's hand, telling him that he only acknowledges the strong, and telling Saitama that he would greet him properly only if he makes it to the higher ranks of S-Class. He also appears to be quite sensitive about being called middle-aged. Kamikaze looks out for his disciples and pushes them to do their best, as seen when his disciple, Iaian, lost his arm, he refused to let his swordsmanship end. However, what he hates the most is being disregarded as a weakling, as he almost loses his composure when Sweet Mask declared Kamikaze weaker than him.
At the same time, he only seems to tolerate people calling his disciples weak, but with great discomfort. Despite his prideful nature, he behaves humbly to those he respects. This is seen with Bang, a fellow hero whom he holds the utmost respect for, and also his fellow Master Swordsmen.
Atomic Samurai also enjoys his swordplay and makes a game out of it, often taunting monsters and showing off as he cuts them to pieces. Specifically, in the raid on the Monster Association, he yawns while fighting Machine God G5 and implies he wouldn't even be good enough as a sparring partner for his disciples, as well as ignoring Rhino Wrestler after cutting him and subsequently killing a monster with the blade of grass in his mouth.
Kamikaze also is straightforward to a humorous degree in many ways, and is incredibly confident and cocky. Atomic Samurai's advice is always to "do it more". This aspect of his personality is most prominently seen when giving advice or improving himself, telling Iaian who had just lost his arm to simply stop bleeding in the fight against the Dark Matter Thieves, explaining to his disciples that to beat people stronger than themselves they simply need to get stronger and faster. Despite this seeming nonsensical, it is inspirational to Atomic Samurai's disciples.
He has unwavering confidence in himself, even when he clearly has no reason to. Atomic Samurai taunts and cuts Black Sperm shortly after losing to him and being saved by Tatsumaki, showing an uncalled for level of confidence in himself.
His confidence has proved to have been his greatest downfall on a few occasions though. One primary example was in his encounter with Black Sperm, a Dragon-level threat with the ability to multiply. Confident he could defeat the monster, he slashed the copies in half multiple times, even though they were replicating into thousands, which ultimately led to his own defeat. He also was very brazen while fighting Melzargard, refusing to find another way to kill him besides melee combat and brute force.
He is also eager to test his strength against strong opponents. As a result, he thought to challenge another hero to battle and test their spirit. He chose King, who was known as "the strongest man on earth". The challenge was proposed out of curiosity about King's fighting style as well since it was largely unknown to him. He remains calm even against the most persistent of enemies.
He has a way of judging a person by having them cut an apple. This was how he chose his three disciples. He later used this method of judgment on King and mistook King's inability to draw his sword (and therefore inability to cut the apple) as him cutting the apple so fast and perfectly that it went back to its original state.
Rather than simply discourage or impress Atomic Samurai, the events motivate him to restart his training, showing an underlying passion for his craft, and a respect for those stronger than him.
Abilities and Powers
Atomic Samurai is one of the top S-Class heroes. He is regarded as one of the most powerful of them, and the strongest backup hero in the Hero Association. He is also considered Earth's strongest swordsman. According to Darkshine, if Garou were to fight him, he would most likely die before being able to show any of his techniques.
He has the ability to perceive a person's life by asking them to cut an apple, which is the method he used to recruit his three disciples.
Immense Speed and Reflexes: Atomic Samurai possesses extreme levels of speed and reflexes, being able to cut his opponents to pieces in the blink of an eye using his sword without them even managing to react. He was able to counter many of Melzargard's attacks, which were extremely quick in their own right. His amazing speed was shown again when he defeated a transformed Haragiri, who claimed to be faster than the speed of sound whilst a human. Atomic Samurai slashed him dozens of times so quickly that Haragiri appeared to have not moved at all. His sword drawing speed is so fast that even Sonic could not see its execution. He was able to slice Rhino Wrestler, a Demon-level monster, into pieces so fast that the monster assumed he had not attacked at all, shortly before dying. Atomic Samurai was also fast enough to react to and cut lightning generated by one of Monster King Orochi's attacks.
Immense Strength: Atomic Samurai appears to have an extreme deal of strength, as he is able to easily cut through solid matter with his sword, as well as create a powerful shock wave with a single slash. His strength is said to be "nuclear-powered." Additionally, he was able to slice a monster into several pieces using only his toothpick. During his fight with G5, he was strong enough to cut apart the tough machine but not its extremely durable core, which he did not anticipate.
Enhanced Durability: Atomic Samurai has very high durability. His amazing durability is shown when he was able to withstand multiple strikes from Black Sperm, a Dragon-level Mysterious Being. Even after being put in a weakened state, he was still strong enough to destroy the roof of the hallway and bring it down on the Black Sperm copies.
Enhanced Stamina: Atomic Samurai possesses a high level of stamina, as demonstrated during his battle against Black Sperm, a powerful Dragon-level Mysterious Being. Despite being severely beaten down by the monster, he managed to remain conscious long enough until Tatsumaki interrupted the battle and shielded him with a psychic barrier. Furthermore, Atomic Samurai was also shown to remain in fighting condition even after having just had a tough fight with Black Sperm when he resurfaced along with the other heroes.
Master Swordsman: Atomic Samurai is an extremely formidable swordsman, so much so that he is considered to be the Earth's strongest swordsman. Legend even says that he can cut down over 100 enemies with each strike. His sword attacks are so fast and strong that the enemies are slashed into many pieces in an instant without even being able to react. He was also able to cut a monster to bits using a mere toothpick. His slashes were even capable of dispersing Orochi's beams. Additionally, Atomic Samurai was able to partially cut off Black Sperm's body without causing the monster to duplicate using the blunted edge of his sword, while also pummeling him to death. 
However, his swordsmanship does have a limit, since he cannot slice through the gap between cells, and he can only prevent his sword from cutting blood vessels or organs, not atoms.
- Atomic Slash (アトミック斬, Atomikku Zan): Atomic Samurai's signature attack. He performs over 100 quick sword slashes within a second, leaving his opponents in pieces. He primarily uses this technique while dashing past the opponent, but has also shown a stationary version in which he slashes everything around himself. Kamikaze is the only swordsman in the world capable of performing this technique.
- Air Blade (飛空剣, Hikūken, Viz: Flying Sword): Kamikaze slashes with his sword and sends a blade of compressed air at his opponents. He can perform the attack upon drawing his sword, blocking an attack and finishing with the air blade in one motion. He taught this technique to Okamaitachi.
- Atomic Beeline Slash (アトミック一文字斬, Atomikku Ichimonji Zan, Viz: Atomic Straight Slash): Kamikaze performs a single and powerful slash in an overhead strike, slicing his opponent. It was first used against the fusion of Psykos and Orochi.
Master Teacher: Atomic Samurai is shown to be very skilled at instructing and raising disciples in the art of the sword. This is demonstrated by his three disciples, who are all at the top of the A-Class rank of the Hero Association, right underneath Sweet Mask himself. According to Fubuki, all of Kamikaze's disciples would have already been in S-Class, if it weren't for Sweet Mask's gate-keeping.
Swords: Atomic Samurai carries two swords: a katana and a wakizashi.
- Katana: His primary blade has a black hilt with a cross-guard that resembles the Rutherford atom model. His primary sword is a custom-made sword, supposedly crafted by a famous blacksmith. The sword's blade was later destroyed by Fuhrer Ugly's acidic vomit.
- Sun Blade (日輪刀, Nichirin Katana): An ancient katana protected by the Council of Swordmasters for generations, and the twin of the symmetrically-named Moon Blade. In his dying breaths, Nichirin gave the sword to Atomic Samurai for safekeeping, imploring the swordsman to find the paired blade. According to legend, anyone who wields both the Sun and Moon Blades simultaneously will obtain unparalleled power as "The Swordmaster."
- Wakizashi: Atomic Samurai carries a wakizashi. The weapon signifies that he is a samurai.
Stick: Atomic can use the stick he normally chews on as a weapon.
- "I only acknowledge the strong."
- "Any problem can be solved by cutting it in half!"
- (To Black Sperm) "Farewell, special blade-testing monster."
- Atomic Samurai is ranked 16th in the character popularity poll.
- According to the databook:
- What he likes are his disciples, worthy opponents, people with great strength, and washed fundoshi (Japanese-style loincloth).
- What he dislikes are weaklings, being called a weakling, interviews, and bothersome things.
- His hobbies are practicing his swordsmanship and traveling with his disciples.
- When he is furious, he transforms into a demon that emits a powerful fighting spirit.
- Kamikaze only allows his best disciples to join the Hero Association with him.
- Atomic Samurai has many disciples within the Hero Association, all of which are ranked quite high among the heroes, such as Iaian, Okamaitachi, and Bushidrill. All of these disciples' names are portmanteaus, containing a Japanese term related to samurai or swordsmanship.
- Murata modeled Atomic Samurai after Kyuzo from "Seven Samurai."
- In the webcomic, his sword's handguard resembled a swastika, but it was changed into the atom symbol in the manga and anime.
- His name holds a double meaning, one for his atom-cutting swordsmanship and two for his nuclear weapons reminiscent strength.
- It should be noted that the word Kamikaze separated means: Kami meaning "god" and Kaze meaning "wind." The combined word literally means "divine wind" or "spirit wind." It was originally the name given in folklore to a typhoon which saved Japan from Mongol invasion by wrecking Kublai Khan's fleet in August 1281.
- Atomic Samurai's fight against Black Sperm was teased back in 2017 in a Halloween cover, where Kamikaze was depicted as the Taketori no Okina (竹取翁, "old man who harvests bamboo"), protagonist of the Tale of the bamboo cutter, whereas three Black Sperm cells were "cosplaying" as bamboo stalks.
- Ichimonji is a famous sword name, for example Kiku Ichimonji was the name of Okita Soji's.