Saitama, the titular character of One-Punch Man, is poised as being an invulnerable being, defeating villains with just one strike. While many consider Saitama utterly invincible, a narrative that the series has purported since the first episode, the reality might actually be quite the contrary. His intense training has certainly raised his status above the average human, though that doesn’t change the fact that he is still only human.
Despite facing off against all sorts of opponents, ranging from beasts to aliens, Saitama remains undefeated with his mighty punch. However, this doesn’t negate the fact that he has several glaring weaknesses, though the series is yet to present a villain that could exploit these shortcomings.
6 Saitama’s Laziness Can Be a Hindrance
Saitama may be the strongest human alive, but that certainly doesn’t mean he’s immune to procrastination and laziness. His laziness has gotten the best of him several times throughout the series, with Saitama usually arriving quite late to the crime scene. By the time Saitama reaches the scene, it's usually just the aftermath of the attack, with no sight of the criminal.
Coupled with Saitama's lack of responsibility as a hero, this can become a serious problem for him. Moreover, he considers being a hero as nothing more than a hobby, keeping him away from the boredom that awaits him every day. With such a mindset, it's no wonder he’s lazy when it comes to being a hero.
5 Saitama’s Attacks Are Ineffective Against Smaller Targets
Saitama’s primary method of attacking is his fists, something that works excellently against larger targets. The same can’t be said for smaller targets, however, as it’s impossible for Saitama to focus the power of his punch in a single area. Since his area of effect is so massive, concentrating on hitting a smaller, moving object is quite impossible.
This was made apparent when Saitama tried to kill a mosquito, a small insect that seemed to be no match for his insane speed. Despite his speed, Saitama remained unable to get rid of the mosquito, with the little insect dodging every one of his attacks with ease. His lack of strategic training also becomes apparent here, as he can’t predict or intercept the movements of his opponents.
4 Lack of Versatility in Saitama’s Arsenal
One punch is all Saitama needs to finish off his opponents, with his mighty punch becoming his signature move to end every single fight. The problem with this, however, is the fact that his fighting style has become too predictable. Since Saitama’s only skills are his speed, strength, and physical invulnerability, finding a workaround to this can be quite simple.
With no martial arts training and no strategic thinking, Saitama always enters the battle head-on, taking on any opponents with his fists. It's only a matter of time before Saitama’s signature style becomes too redundant, and his shortcomings become victim to exploitation.
3 Saitama’s Low Intelligence Can Sometimes Be a Problem
Saitama has clearly demonstrated that he possesses some semblance of intelligence, yet it doesn’t negate the fact that he clearly isn’t the sharpest tool in the shed. Saitama’s lack of intelligence could very well become one of his biggest weaknesses, with villains only requiring wits to outsmart the famed hero.
Saitama’s answer to most obstacles is to simply punch his way through, and while this may have worked in his favor every time, some problems may require a bit of actual brain power. Any situation that requires using a bit of brain muscles could easily turn against Saitama, such as a potential hostage situation.
2 Saitama’s Lack of Combat Training
One of Saitama’s most prominent weaknesses is his lack of combat training. He was able to achieve his god-like strength through a strict work-out regimen, comprising 100 sit-ups, squats, and push-ups, followed by a 10-kilometer run. While this training surely granted him unfathomable power, it lacked any sort of combatant training.
Other heroes have trained in several schools of martial arts, honing their fighting skills through proper training. Saitama never received any sort of training in this regard, making his fighting style simply revolve around throwing punches. This weakness can easily be exploited by those more proficient in the fighting arts, easily making use of the openings in Saitama’s attacks.
1 Saitama Is Only Human
While Saitama’s strength may be beyond human capabilities, he himself is still a mortal human, vulnerable to the same woes as any other person. His body has undergone several augmentations due to his strength, as witnessed in his ascent into space without any sort of equipment. His body may have survived such harsh conditions, but only for a certain while, requiring him to re-enter Earth to breathe.
This opens up several ways for Saitama’s opponents to defeat him, as they could employ tactics that could exploit his human weaknesses. Trapping him in outer space or potentially drowning him are all ways that could be employed to debilitate Saitama, with his human weaknesses easily dethroning him for the title of the ‘strongest hero.’