Anime heroes are used to saving the world but not many of them can say they've actually changed it. Saving the world usually means returning things to the status queue. Not to mention, the actions of most heroes go unrecognized by the people around them.
However, some heroes are so important to their community that they actually change how society functions. Ridding the world of evil organizations or war makes a huge impact but unfortunately, there can be a lot of negatives to a hero making such significant changes to the world around them.
10 Hashirama Created The Current Shinobi System
Naruto
Hashirama isn't just the first Hokage in Naruto. He's a man who changed countries. He established a system of government that ended the war between clans and stopped countless deaths from continuing.
Hashirama is the most influential man in anime because his system didn't just affect the people around him. The entire world adopted it. He is far from a perfect man. It's his fault that Madara turned to evil, but not many people can say they single-handedly brought peace to the world.
9 Usagi Created The Universe
Sailor Moon
Sailor Moon may be an average teenage girl, but she's also a powerful Sailor Scout who's literally changed the universe. Some fans would be surprised by how strong she is, but her magic gives her the ability to completely control reality.
The most powerful villain Sailor Moon faces, Chaos, completely destroys the universe during their fight, and she fully recreates it with her attacks. Considering how powerful Usagi is, it's a good thing she fights for the protection of the universe and not evil.
8 Lelouch Freed Japan
Code Geass
Although Lelouch may just be a student, he is an incredibly intelligent and manipulative one. It's thanks to his influence that the rebels were able to stand a chance against Britannia. He may have been acting for his own gain, but his impact allowed Japanese citizens to get their own territory outside Britannian influence.
Not to mention, the rebels were able to grow into the Black Knights with incredible power and influence. Even his death enacts great change in the world. By allowing himself to be killed, Lelouch allowed the people to become free from Britannia.
7 All Might Changed The Hero World For Better & Worse
My Hero Academia
The world was a dark place before All Might took his spot as the Number One Hero. During the first movie My Hero Academia: Two Heroes his friend David Shield even states that the crime rate in Japan is so low because of All Might's influence. While his work as a hero helped to significantly decrease the amount of crime, his influence on the public was much more important.
As the Symbol of Peace, he created a net of safety that gave people hope. This was a good thing in his heyday but being such an influential hero completely backfires when he no longer has the power to protect people. The fact that the world fell to chaos without him around shows how significant his role as a hero was.
6 Ed Changed The Source Of Alchemy
Fullmetal Alchemist: Brotherhood
Edward Elric is a prodigy alchemist in Full Metal Alchemist: Brotherhood. He isn't the strongest alchemist, but he's had the greatest influence on the state of his country Amestris. His research into the philosopher's stone reveals the corruption running rampant in the government. He also finds out the Homunculi's plans to wipe out every living being in the country.
In fact, Father and his Homunculi succeed but it's thanks to Ed's intervention that every human is able to get their soul back. Not to mention, by defeating Father, Ed changes the source of alchemy, which had been completely controlled by Father.
5 Goku Saved The Planet
Dragon Ball Z
Goku has had a huge influence on the world of anime, but he's also incredibly influential when it comes to his own universe. Earth has been at risk of destruction so many times it's a miracle the planet still exists.
Thousands of people have died at the hands of Dragon Ball Z's various villains but Goku and his friends are always able to bring them back with the power of the dragon balls. As a hero with a pure heart, Goku has also changed many people to his side. If he hadn't turned Vegeta from an enemy to a friend Bulma wouldn't have found the love of her life and Trunks wouldn't exist.
4 Gol D. Roger Created The Pirate Age
One Piece
Gol D. Roger is a legend among pirates in One Piece. He was King of the Pirates in his heyday and his death helped create a new age of pirates. Whether they hate him or worship him, every person knows the name Gol D. Roger, which is a testament to how influential he is.
It's likely the pirate age would have ended with Gol D. Roger if he hadn't encouraged people to search out his treasure — the One Piece. It makes sense that the government tried to eradicate anyone associated with Gol D. Roger considering most pirates admire him and his crew like royalty.
3 Eren Helped His Friends Fight Back
Attack On Titan
Before Eren Yeager comes along, humanity is at the Titans' mercy. They have no idea where the giant creatures are coming from and there is nothing they can do to fight back. Eren's Titan form gives humanity a fighting chance, but he also gives them an opportunity to understand what's happening in the world around them.
Not to mention, Eren's influence over the Scouts helps remove corruption from within the walls and the people stopped being slaves to the king. Unfortunately, Eren changes from the savior of humanity to their greatest villain but he still enacted a lot of change that helped people.
2 Madoka Saved Every Magical Girl
Puella Magi Madoka Magica
When Madoka agrees to become a magical girl in Puella Magi Madoka Magica her only goal is to be an amazing magical girl like Mami. It isn't until after she becomes a magical girl that she realizes that being a magical girl isn't all it's cracked up to be.
Not only is her soul removed from her body, but magical girls run the risk of becoming the witches they are fighting to exterminate. In an attempt to save every magical girl, Madoka makes a wish that will give her the power to destroy every witch before it's created. Thanks to her, magical girls no longer have to worry about becoming witches.
1 Saiki Changed Humanity To Fit In
The Disastrous Life of Saiki K
Saiki from The Disastrous Life of Saiki K may be extremely powerful, but he isn't trying to make a name for himself. Any changes he makes to the world are to help him fit in better and make his life easier.
Saiki even gives humans the ability to have unnatural-colored hair just so he can fit in better with his peers. Most of the time, his influence over the people around him is so subtle most people don't even notice it, which is exactly the way he likes it.