Supreme Hero Arc

The Supreme Hero Arc is the nineteenth arc of the One-Punch Man series, and the fourth arc of the Neo Heroes Saga.

Plot
Saitama encounters Rangor, one of the nine warriors of the Dragon Alliance, and defeats him with a single punch. He then comes across a group of people calling themselves the Saints. They explain how by defeating Rangor, Saitama has protected the Cruel Dragon seal and saved the world, and then tell the legend of Cruel Dragon: a creature that descended upon Earth, taking countless lives and scorching the land. They explain that ancient warriors managed to weaken the dragon with costly sacrifices, allowing seal masters to seal away the essence of the dragon in nine seal stones, which are now scattered in temples across the land. This brought rise to two groups: the protectors of the seal stones, the Saints, and a group hoping to resurrect the dragon, Deathbone. The two groups have been in conflict for 800 years, but Deathbone recently increased their activity, taking advantage of the recent frequent monster incidents. One of the Saints hold down a member of Deathbone, who begins to monologue as he loses consciousness, until Saitama throws a bucket of water on his face. Saitama eventually resolves that if the dragon will resurrect at some point, it would be smart to resurrect it promptly to defeat it quicker. Much to the Saints' dismay, Saitama picks up the Deathbone member and flees from the Saint members chasing after him, who help him locate all nine seals. After the Deathbone member conducts the ceremony, the Cruel Dragon resurrects, and Saitama defeats it with a single punch.

Saitama picks out groceries.

Later that night, Saitama meets up with Genos on a street leading towards former A-City. Genos is visibly damaged and explains that it is from a battle against a powerful demon level monster when Saitama asks, and requests another spar with Saitama. He then mentions that Dr. Kuseno has shown great interest in Saitama's physical abilities and wishes to collect his data. Saitama asks Genos what he bought and Genos lists the items, adding the fact that he got them for cheap. Saitama is impressed by this and compliments him by telling him that he's mastered the trick to buying stuff, even admitting to missing out on some AAA batteries at half price. Suddenly, the two encounter Sweet Mask who offers to meet up for a cup of tea tomorrow noon as he wants to discuss something in person. Genos refuses the offer, believing that Sweet Mask is talking to him, but it is then revealed that he was speaking to Saitama.

The next day, Saitama and Sweet Mask are sat on a table in a cafe. A waiter approaches them and asks what they would like; Saitama orders a coke and Sweet Mask orders a lemonade, but Sweet Mask orders a ginger ale for Saitama instead of the coke, which irks him.

Later, Sweet Mask has lunch with Saitama and tries to teach him how to be a good hero. Saitama ignores most of what Sweet Mask has to say, so Sweet Mask decides to move somewhere else to continue his talk. They walk to a carnival and sit in a Ferris wheel cabin. Now able to speak in secrecy, Sweet Mask reveals his past to Saitama. He explains that he was born an unsightly human, so he adhered to strict moral principles to compensate for his ugliness. He started working as a hero, but his overwhelming loathing for his looks resulted in a transformation that turned him into a monster with a beautiful face. Sweet Mask then tells Saitama that he is the one person he found worthy of carrying on his legacy and becoming the ideal hero. Saitama turns down the offer and jumps out of the cabin to meet Genos.

Suddenly, a commotion on the fairgrounds catches Sweet Mask's attention. The cause of the ruckus is Pesky Clown, who had killed several guards that had attempted to stop him. The monster swings his mallet to hit a civilian, but Sweet Mask shows up and stops the attack. The two engage in combat. Sweet Mask has the upper hand at the start of the battle and destroys three of the monster's life balloons. However, the monster draws power from the attention of the crowd and transforms, becoming powerful enough to overpower the hero. Sweet Mask then decides to unveil his monster side in order to defeat Pesky Clown.

Sweet Mask then returns from the rubble to engage the monster again. Outside of the fairgrounds, Saitama runs into Genos, who is on his way to the monster sighting to aid Sweet Mask. At the scene of the battle, Sweet Mask has successfully overpowered Pesky Clown using his monster form. The civilians still gathered there now catch sight of Sweet Mask's unsightly face and begin to question if he is actually a monster. Pesky Clown uses the worldwide attention Sweet Mask is recieving to increase his power even more, giving him a gruesome transformation, and the two engage in combat once more. The two fight desperately until Sweet Mask finally dispatches Pesky Clown with a brutal punch.

Now that the people can clearly view Sweet Mask's true appearance, he is berated as people begin to fear him. Blue Fire arrives with the intent to support Sweet Mask in battle only to not be able to recognize him until he is pointed out by a member of the crowd. Like the others, he is fearful of Sweet Mask and classifies him as a monster. Saitama is the next hero to arrive, and catches a rock thrown at Sweet Mask. Instead of berating him like the others, Saitama supports him. Sweet Mask doesn't acknowledge this and wants Saitama to kill him, hoping that Saitama will be seen as a hero for defeating him. Saitama ignores the request and continues supporting Sweet Mask. Sweet Mask attempts to attack Saitama, latching his hand around Saitama's head in order to show his strength. Saitama jumps away, carrying Sweet Mask with him. The news of Sweet Mask's true appearance continues to spread and he becomes more and more disliked by the general public. The news is regarded as the beginning of the Hero Association's collapse.

Later, a Hero Association scouting team makes its way to Suicho's dojo. They are met by Suiko, Suicho's granddaughter and Suiryu's younger sister. She asks the scouting group if she can join the Hero Association as an S-Class hero and comes back with them.

At the Neo Heroes headquarters, several Neo Leaders converse about the situation surrounding Sweet Mask. Webigaza is emotionally impacted by the situation, remarking that she wanted to defeat him herself. McCoy figures that the Hero Association is beginning to fall apart and that the Neo Heroes are officially on the same authoritative level as them. Darkshine and Metal Bat wonder where Blue is, considering he is number one in the Neo Heroes and hasn't shown himself. It is revealed that he left to pursue the case surrounding Sweet Mask.

In the Hero Association headquarters, three heroes are considering joining the Neo Heroes after being scouted. They discuss the benefits of the Neo Heroes compared to the benefits of the Hero Association, and come to the conclusion that the Neo Heroes would be much better for them personally. Rover and Black Sperm are present, and Black Sperm thinks about the current situation, that two rival Hero associations are combatting instead of focusing on working together to fight monsters. He remarks that the current situation will be beneficial for the two monsters, with the effectiveness of heroes slowly declining. Saitama approaches the three heroes and is asked if he has been scouted by the Neo Heroes. Suddenly, a Neo Heroes group approaches Saitama and asks to have him as a leader because of his unfortunate hero name. Black Sperm continues to ponder, using the Neo Heroes group as proof that the Hero system is close to failing.

Suiko arrives at the Hero Association headquarters and is welcomed in. While being led to the training grounds, she is told that her brother, Suiryu, won the Super Fight tournament and that the Hero Association wants him as a hero as well. Suiko says that that isn't necessary, and that she is stronger than Suiryu. In the training grounds, Suiko demonstrates her strength by easily destroying a training robot. She is disappointed that this feat landed her in A-Class and not S-Class.

At the Neo Heroes headquarters, Suiryu is being escorted by McCoy. He seems to not take what McCoy is saying very seriously about what he should do as a hero, instead he simply understands that he needs to defeat monsters and he will get paid. Outside of the headquarters, Genos and Saitama spar in order for Genos to collect battle data from the fight. Genos questions to himself what happened between Saitama and Sweet Mask after the two left the amusement park. Genos remarks that the look on Saitama's face is different from the usual. It turns out that Saitama was just thinking about the Hero Name Victims Association.

Later, Suiryu is introduced to the Neo Leaders and McCoy tells them that Suiryu will be a leader. Next, each of the Neo Leaders are similarly introduced. Raiden is introduced as an impressively strong sumo champion who is claimed to even surpass the S-Class. Raiden notes that Darkshine is quite well known and asks to compare the two's strength. The lock hands and Darkshine seems to be slightly overwhelmed by Raiden's strength. After the bout, Raiden believes that Darkshine might be past his prime. Suddenly, two Leader candidates barge in, angry that they were not accepted to be leaders. Mars Leo shows off his speed and lets one of his punches hit Darkshine, breaking his own wrist. Suiryu buts in between the two, and is attacked by both of the candidates, effortlessly fending off their attacks. McCoy continues with introductions, and the two leader candidates are ushered away by Erimin and Destro. McCoy concludes by introducing Blue, who had just arrived. He explains that Blue is the reason the Neo Heroes exist.

Then, a flashback shows how Blue chased Saitama and Sweet Mask. In order to keep up with the two, he removed the limiter on his suit and likely began speeding up. Before long he is stopped by Genos who asks what he is doing. Blue asks if this is the Hero Association's attempt to protect Sweet Mask and also questions Saitama's speed. Blue implies a threat, and wants answers from Genos. Genos says that he doesn't know what Saitama will do with Sweet Mask. Back in the present, Blue explains why he created the Neo Heroes, before being revealed as Blast's son.

Story Impact

 * Sweet Mask reveals his past to Saitama.
 * Sweet Mask is revealed as a monster to the public and is forced to retire.
 * Blast's son is revealed in Blue.