11 Heroes Who Witnessed Saitama’s True Strength In One Punch Man!

There’s no doubt that Saitama is the strongest character in the series, thanks to his insane workout routine. However, he isn’t at the top of the S-Class ranking. In fact, he is just a B-Class Hero!

Saitama’s true strength has remained a mystery for the Hero Association and most people. However, there are a few characters in the series that have witnessed Saitama’s true strength!

In this article, we are going to take a look at every Hero that knows Saitama’s true strength! 

1) Genos:

The first hero to ever understand Saitama’s strength was his disciple, Genos.

During the second episode of season 1, Genos was fighting a Demon-level threat called the “Mosquito Girl” in Z-City. 

Genos finds out Saitama's true strength

A wild Saitama appeared, chasing a puny little mosquito. Like most people, Genos didn’t understand Saitama’s true potential at the moment due to Saitama’s lack of a strong aura.

However, when Genos was going to sacrifice his body to kill the Mosquito Girl, Saitama hit the monster with a firm slap. To Genos’ surprise, the monster exploded in an instant! 

Genos then became Saitama’s disciple and requested a sparring match. Saitama then split the clouds with a single punch, making Genos truly realize Saitama’s true strength! 

2) Bang: 

In the 7th episode of season 1, a meteorite of 200m in height was about to hit city Z after a sudden change in its trajectory! 

This meteorite was declared to be a Dragon-level threat, and its clash would cause the destruction of City-Z and neighboring towns. Therefore, the Hero Association requested an emergency help call to all S-Class heroes!

Bang One Punch Man

However, only three S-Class heroes were close enough to reach in time: Genos, Bofoi aka Metal Knight, and Bang. Metal Knight attacked the meteor with its super missiles but couldn’t even make a dent and left. 

Genos tried his hand too and even fired off his Incineration Burn attack at full power. However, it was to no avail. And Bang, S-Class Rank 3 couldn’t do anything as he’s a martial artist and lacks the range to even try to stop the metor. 

This is when Saitama showed up. He jumped into the sky and obliterated the metor with a single punch. Bang said that Saitama was peerless and became a fan of Saitama since that day! 

3) Fubuki: 

Fubuki, B-Class Rank 1 paid a visit to Saitama after he was promoted to rank 5 in the same class. She wanted Saitama to join her team. 

Fubuki OPM

However, Saitama didn’t care and shut the door in her face. Fast forward a few minutes and things have escalated quickly. Genos, the S-Class Hero gets outsped by Speed-O-Sound Sonic. 

Saitama steps up to the fight, and much to Fubuki’s surprise, the B-Class hero won by a landslide. 

4) Mumen Rider:

During the Deep Sea King Arc, Mumen Rider put up a gut-wrenching, tear-jerking, making you feel like a true man fight, even though he knew that he was hopeless. 

Mumen Rider Finds Out Saitama's True Strength

Saitama then saved Mumen Rider and one-punched the life out of Deep Sea King, saving everybody in the process.

While the Hero Association’s insanely flawed system couldn’t comprehend Saitama’s strength, Mumen Rider did. He later gave a ramen treat to Saitama, and also gave him a ride on his bicycle! 

The two have maintained their friendship since then, as Saitama even visited Mumen Rider after he was hospitalized by Garou. 

5) King:

King was living his “normal” life, pretending to fight monsters and playing idol games at home. Suddenly, a random bald dude climbed into his house, which was on one of the top floors! 

King One Punch Man

This was obviously Saitama, who wanted to ask King a question; Why did he not fight G5? At first, Saitama assumed that this was because King was too strong, just like him, and didn’t want to fight anybody.

However, things took a turn as a massive bird monster attacked King’s apartment. 

King is obviously weak and had pissed his pants by this time already. While he believed that both he and the bald guy were going to die, this wasn’t some random bald guy. 

It was the Caped Baldy himself and hence, he one-shotted the bird! This is when King realized that Saitama had saved him multiple times. And, that it was his feats that people believed to be King’s, calling him the world’s strongest. 

King also realized that it was a pre-bald Saitama who saved King on the day he got his iconic scar! 

6) Zombieman: 

Zombieman was not fond of Saitama’s presence at the start, due to the major difference in rank between the two. 


Even though Dr. Genus, the guy who made him immortal stated that Saitama was strong, Zombieman never believed him. That was until chapter 90 of the webcomic, where Saitama fought Garou and won overwhelmingly. 

In this scene, you can see Zombieman witness Saitama’s overwhelming strength in all its glory, with no chance of a facade or a weakened enemy. He wanted to believe that it was because all S-Class heroes fought Garou, but deep down he knew the truth.

That’s exactly why he went back to Dr. Genus after the Monster Association Arc. Zombieman begged Dr. Genus to make him as strong as Saitama, to remove his limiter. 

7) Flashy Flash: 

Flashy Flash, the S-Class rank 13 hero is said to be the fastest on the planet. But one day, he accidentally hit a random person! 

Flashy Flash One Punch Man

At this moment, the S-Class Hero’s career flashed through his eyes. Fortunately, it was Saitama. 

When a random B-Class hero dodges your attacks, you might be confused, and so was Flashy Flash. While he initially believed it to be a fluke, their journey through the underground together only proved to be more mind-boggling! 

Saitama did everything that Flashy Flash couldn’t, like lifting God’s cube and even obliterating multiple monsters with ease as well as keeping up with Flashy Flash’s speed whilst jogging. 

Later, Flashy Flash was convinced that Saitama was as strong as any S-Class Hero.

8) Amai Mask: 

Amai Mask became interested in Saitama quite early in the story. After the Deep Sea King arc, we see a scene where Amai Mask was shown footage of the sea monster’s defeat, and it is apparent that the top-ranking hero was impressed. 

Amai Mask OPM

It was as if he was waiting for Saitama to reach the top! 

Later on, he witnessed Saitama’s fight against Garou and became obsessed. To Amai Mask, Saitama was the true hero, the gold standard of overwhelming power. Because of this, he had aspirations to transform Saitama into the world’s greatest superhero!

9) Dr. Bofoi (Metal Knight): 

After the damage caused by the Monster Association, Bofoi used the Hero Association and the Government’s money to create the strongest robots. 

Dr Bofoi

Unfortunately, these robots ended up attacking Saitama after considering him to be an intruder after he tried to enter with his two newly adopted pets Rover and Black sperm.

Upon reviewing the footage, it became clear to Bofoi that Saitama was the real deal. 

10) Blast: 

Next up we have Blast, the number 1 hero of the world. Said to only step in when Earth faces a god-level threat, Blast came to Earth to stop Cosmic Garou, who had partially accepted God’s powers.

Blast and Saitama

Whilst the whole Garou situation was surprising enough already, what really blew Blasts’ mind was an unexpected contender. Saitama! After Garou “killed” Genos, Saitama nearly obliterated the whole planet in a single punch. 

Blast had to deflect his strongest punch with the help of his comrades, shaking the Hero’s understanding of the planet. 

11) Tatsumaki: 

In the webcomic, the two giants of the Hero Association, Tatsumaki, and Saitama, clashed over their ideals. During the Psychic Sisters Arc, Tatsumaki was forcing Fubuki to leave her crew. Saitama stepped up for Fubuki, clashing with the 2nd-ranked S-Class hero.

Saitama and Tatsumaki

This led to another classic fight. Tatsumaki, although still recovering from a split head injury, tried to crush Saitama, and failed. 

Their clash included tornadoes, massive pieces of rocks floating, the Earth splitting open from time to time, and whatnot.

She called Saitama a weirdo for being so strong and hiding all of his powers as a low-ranker, Tatsumaki then proceeds to promise to fight him again after she recovers.