Mumen Rider also known as Satoru is one of the well-known characters from the One Punch Man series.
At first, no one thought much about Mumen Rider, not even the audience.
After all, he is just an ordinary person without any enormous strength or any other kind of superpower compared to many other characters we see.
Nothing but an ordinary cyclist, eager to help others. But from that moment and only from that moment everyone sees him as a real hero.
Not because he is powerful, not because he wins the battle, but simply because he puts everything into being a true hero.
Even when faced with the most unfortunate circumstances, he is not ready to give up.
Equipped only with a determination to protect the people and a brave heart.
Mumen Rider is ready to face an enemy who could kill him so easily at any time.
He does his best to be a hero, not for fame or money. He sanctifies everything for the benefit and well-being of others.

To protect those who are too afraid or weak to fight and to show people that there is still hope and to reassure them, even if it’s just a small chance that everything will be fine.
Mumen Rider acknowledges his weakness, that there might be no chance of victory.
Yet, he gives everything he has. And that’s why people rejoice in front of him.
So everyone shouted for his victory and was ready to believe in him.
Saitama & Mumen Rider

Mumen Rider is one of the most heroic characters in One Punch Man so far.
I think through him we are shown that the general public loves this guy, despite his lack of power.
We all think he is a very cool hero. But, Saitama seems to be the only hero in the One Punch Man series who simply sees and understands his moral beliefs.

When Mumen Rider attacks the Deep-Sea King, he does not expect victory.
But a hero who fights only when he can win is not really a hero. He struggles to delay and distract the King of the Deep Sea as much as possible.
In a desperate and vain hope, he also understands that a hero strong enough to defeat the monster needs to appear.
Completely ready to be destroyed if no other hero makes it on time. He seems to be at least dimly aware of his limitations.
He knows that the King of the Deep Sea is one of the most serious threats the entire city has faced so far, at least for a very long time.
But he thinks the fight against him is right. So, he will do his best.
He fought only because the situation was extremely desperate, and failure meant that all civilians would die.
Saitama seems to have understood almost all of this. He has a lot of respect for the cycling hero.
It’s easy to assume that Mumen Rider is just going to be a character that would have any significant contribution to the plot.
But it seems to me as a viewer that he is quite rational and extremely heroic.
Mumen Rider performed well against Deep Sea King.
He did everything he could to help civilians in need.
Saitama saw this and acknowledges him as a true hero even if he is a class C hero with no special powers up his sleeve.
The respect that Saitama has for Mumen Rider stems from his sense of justice and being a ‘true hero’.
Thanks for reading!