Suiko

Suiko (スイコ, Suiko) is the A-Class Rank 40 professional hero of the Hero Association. She is a martial artist and a user of Void Fist. She is the younger sister of Suiryu and the granddaughter of Suicho. After Saitama saves her, she becomes aware of his strength.

Appearance
Suiko is a young woman with a lean build. She has dark eyes, tan skin, and short black hair. She wears a dark Chinese-style martial art uniform with white linings, long sleeves, and star-shaped buttons.

Personality
Suiko is an easygoing woman, if not a little naive. She is somewhat arrogant as to occasionally overrate her own abilities but is not afraid of improving herself.

Despite this, she is not one to put herself above others, as she was thankful to Saitama for saving her against Mirror and even called him much stronger than her own brother, Suiryu.

Supreme Hero Arc
Suiko is approached by a Hero Association scouting group in her grandfather's dojo. The group asks for Suicho and wants to make him an S-Class hero, only for Suiko to tell them he is dead, so she offers to become a hero in his place. She travels to the Hero Association headquarters and is escorted to a training room by staff. On the way, she is asked about her brother Suiryu, who the association wants to contact for hero work as well. Suiko replies, saying that she would be a much more reliable hero than Suiryu. After a quick bout where she easily destroys a training robot, she is given an A-Class position, much to her disappointment, her original goal being landing in S-Class. Even so, she promises to herself she will make a name for herself as a hero.

Neo Heroes Uprising Arc
Suiko is next seen outside of the Hero Association headquarters, spectating the complaints of the Hero Name Victims Association and noting the group as heroes she doesn't want to become. After hearing the announcement warning of 5 Dragon-level monsters being spotted, she heads to Y-City to confront Mirror.

The fight quickly goes sour as Suiko is unable to keep up with Mirror, only being able to dodge. She questions her strength as she is thrown into a store by the robot. She lands in front of a shelf filled with drinks, which she scans through for a drink with the highest alcohol concentration. After finding one, she drinks it. This seems to boost her performance notably, as she is able to land hits on Mirror, though none of them do damage.

The fight is interrupted by Chain'n'toad and Butterfly DX who arrive as support. Suiko takes the opportunity given by the two heroes and hits Mirror using Void Quake Tiger Fist, which is largely ineffective. The battle turns into a beatdown as all three heroes are easily taken out.

The Hero Name Victims Association arrives to fight Mirror next, Suiko warning them that there is no chance of winning. She watches as Saitama easily kills the robot, and is so shocked by how easily he dispatched it that she pinched her own cheek to make sure she wasn't dreaming.

She later on meets with Saitama and wants to exchange some fighting technique as she acknowledges his power until her older brother arrives, which she glads that he manages to find a proper job. She introduces him to Saitama and states that he is stronger than Suiryu but he does not believe her.

As a compliment to make Suiko acknowledge his power, Suiryu permits Suiko to date Saitama. Suiyu persuades Suiko to join the Neo-Heroes and willing to put some recommendation to Saitama but Suiko declines as she does not want to be in the silly battle suit.

Abilities and Powers
As a student and granddaughter of Suicho, inventor of the Void Fist, Suiko is a very powerful fighter and can be assumed to be around the same level as Suiryu, although Suiko claims to be stronger than him. Unlike her brother, she is more disciplined and takes on improving her own skills more seriously. Suiko was able to secure an A-Class rating from the Hero Association after only a brief demonstration. However, against a Dragon-level monster like Mirror, she is helpless, as one of her strongest attacks was only able to deal 0.4% damage to the Machine God.

Physical Abilities
Immense Strength: Suiko naturally has impressive strength, likely due to her relation to her grandfather. She was able to easily destroy one of the Hero Association's training robots with her Void Revolving Tortoise Fist. She also had enough power to scratch a Dragon-level threat, a feat that most heroes outside of the S-Class can't accomplish, though she still couldn't do any substantial damage to it.

Immense Speed and Reflexes: Suiko possesses impressive speed and agility. She was able to easily dodge a punch from a training robot of the Hero Association and destroy it before it could retaliate. Suiko was also able to keep up with and dodge several attacks from Mirror, a Dragon-level threat, albeit barely.

Fighting Style
Master Martial Artist: Suiko is a well accomplished martial artist and claims to be stronger than her brother.


 * Void Fist (冥躰拳, Meitei-ken; Viz: The Dark Body Art or Dark Corporal Fist): This style focuses on maximizing damage output, while keeping a consistent flow of damage. The martial art utilizes shifting the user's center of gravity for attack and defense.
 * Void Revolving Tortoise Fist (冥躰廻亀拳, Meitei Kaiki ken): A technique similar to Void Sky Dragon Fist. It is shown to be strong enough to pulverize a Hero Association training robot.
 * Void Quake Tiger Fist (冥躰震虎拳, Meitei Shin Koken): Suiko drives her foot into the ground and throws a heavy punch.
 * Void Sky Dragon Fist (冥躰空龍拳, Meitei Kūryū Ken): Suiko attacks her opponents rapidly with a barrage of kicks to the point of creating tremendous momentum that makes her twist like a tornado in mid-air. The momentum she creates from her repeating blows preserves her mid-air rotations.
 * Drunk Tiger: Suiko becomes intoxicated in order to make her fighting pattern more unpredictable.

Trivia

 * In ONE's first storyboard, Suiryu was Lin Lin's brother. ONE ended up using the sibling idea to create Suiko.
 * In one of Murata's streams when describing what ethnicity the characters would be in the real world, Murata stated that Suiryu looks Italian. Meaning he would likely think the same for Suiko considering the large resemblance she bears to her brother.
 * Suiko's name is a pun on 遂行 (Suikou), "Accomplishment" and 酔拳 (Suiken), "Drunken Fist".
 * Suiko's appearance and personality might be based on Rock Lee from the Naruto series:
 * Her haircut and eyelashes are very similar to Rock Lee's.
 * Her passion for training and improving her strength are reminiscent of Rock Lee's own approach to training.
 * Just like Rock Lee, Suiko is a master of the Drunken Fist, even though unlike him she is aware of it, and will intentionally drink alcohol to use it.
 * In the manga, her brother, Suiryu was the first one to know and acknowledge Saitama's strength.