Heroes started appearing when the Quirk phenomenon occurred and the general populace acquired superpowers. The dawn of this extraordinary era was plagued by a breakdown of society caused by the sudden onslaught of criminals empowered by their newfound abilities and ordinary people being prejudiced against the Quirk users. As society adapted to the new status quo, the Police Force moved to prioritize leadership and to maintain the status quo, and as such, decided not to use Quirks as weapons.
As chaos and unrest ensued due to the outbreak of Quirks, ordinary civilians with their own Quirks decided to take matters into their own hands to bring order to society, and thus the first "Heroes" appeared. These original Heroes to appear during this time of chaos were Vigilantes, as the Pro Hero system had not yet been implemented, beginning the time period known as the Vigilantly era. Later on, the profession of crime-fighting Quirk users separate from the police and military, and Pro Heroes, began to exist.
Which led to what was going on in Nedzu's office as the Srawhats were talking with him and another person.
She was the Head of the Hero Commission in Japan.
"You want us to act as Pros?" Ace asked.
"Yes, while I am aware that you don't like to be called heroes for your..............odd reasons......I'd like for you to take this role at least until you can return home. We can even arrange costumes for each of you and organize a temporary base for your operations until then. Anything else will be at your description and we could use the help concerning the League of Villians is still at large." She said.
"The same guy that attacked the USJ? You think they could attack again?" Nami asked.
"While they haven't done anything yet, we can't lower our guard, especially since we have All Might teaching now which makes U.A. an even bigger target for them."
"Ah, so they can threaten Green Bean and his friends again? O.K." Luffy said.
"Green Bean?"
"That's what he calls one of the students, Midoriya." Yukiko explained.
"Ah."
"There you have it. We'll be helping since we have nothing else to do until we return." Alina said.
"Good. In addition, we need for you to have a hero name if you wish." The Commissioner said.
"We already call ourselves the Strawhats thanks to Luffy, we'll be the Strawhat Crew, with individual names."
With a little discussion they found some names:
Alina:
The Summoner Hero: Yuusha
Ace:
The Pyro Hero: Flame Emperor
Bonney:
The Age Hero: Childiren
Jinbei:
The Karate Hero: Xiaolin Mariner
Brook:
The Musician Hero: Soul King
Franky:
The Cyborg Hero: Supersteel
Robin:
The Mysterious Hero: All Sunday
Chopper:
The Miracle Medic Hero: Dr. Sakura
Sanji:
The Kicking Hero: Black Leg
Usopp:
The Marksman Hero: Sogeking
Nami:
The Forecast Hero: Weatheria
Zoro:
The Blade Hero: Ronin
Yukiko:
The Jeweled Moon Hero: Selene
Luffy:
The Sun Warrior Hero: Joyboy
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After getting their own outfits as their costumes, they had to do a patrol in different cities.
As always, Luffy, Yukiko, and Pachi stuck together and Chopper decided to tag along.
Sanji went with Nami and Robin.
Usopp went with Franky.
And Bonney, Brook and Jinbei decided to take Zoro with them for patrol.
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"So you are holding off piracy to be heroes?" Rosetta asked.
"Yeah, till we can get back home, besides that Handyman that attacked Green Bean and his friends is still out there. I wanna find this guy and kick his ass!" Luffy yelled.
"Well, it is not going to be easy. Besides, he may actually be taking orders from someone else since I figured he was too childish to conduct the attack on his own." Yukiko said.
"By the way, I heard the Nedzu offered you two to train Pros to use Haki?" Yukiko asked.
"Yup, those bean sprouts will need to be ready for what may come their way, especially after what you told us." Rosetta said.
"Well, we are off! Can't keep our new students waiting ya know!" Garp laughed as he and Rosetta left.
"How long do you think they'll last?" Yukiko asked.
"I'll bet five minutes." Luffy said.
"Two and a half, it's your grandmom too." Yukiko adds.
"Oh, yeah."
Then, they went their own ways.
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Sometime during their patrol, they heard a commotion.
"What's going on?" Chopper asked.
Yukiko used her Observation and tensed.
"A hero and a student from U.A. have been attacked! It is the Hero Killer they have been talking about!"
"Chopper! You get into heavy form and look for injured people. Tell them you're a Rescue Hero! Yukiko, you keep any civilians from getting harmed, I'll face Stain!" Luffy commanded.
They quickly went into action.
Yukiko made a moonstone aura barrier to keep Stain from attacking anyone, and Chopper moved to get people out of harm's way.
Stain looked at the new arrivals.
"So you intervened in my judgement..........you're the new batch of heroes I've been hearing about. Let's see what kind of hero you are Joyboy." Stain then rushed to attack Luffy.............but he could not land a single hit.
"Gum Gum..............Bullet!"
He then hit Stain in the face, leaving a nasty bruise in a fist shape.
"Ack, that was a good hit. Tell me, why did you intervene in my hunt? To gain fame from capturing me?"
"You were about to kill Specs, and you harmed his brother. I never met them, but I could not let Specs die. His brother would be sad and blame himself. That's all the reason I need." Luffy said flashing back to Marineford.
Stain was surprised at this answer. 'He's fighting me to help a friend? Huh. guess there may be some hope for this society after all.'
As the fight continued, Luffy got the go from Yukiko that the civilians have all been evacuated.
"Alright! Gear Second!" Luffy began steaming up and his skin turned pink.
'What the?!'
"Gum Gum....................." Then Luffy disappeared and then reappeared above Stain faster than he could say 'All Might.'
And...
POW!
Stain found himself on the ground pummeled into the ground.
"Jet Gattling!"
Meanwhile in the corner of her eye, Yukiko spotted another of those strange creatures about to attack Chopper.......
If she did not take it down with a Crystal Laser to the head, killing it.
But, the crowd cheered as the new heroes, Joyboy, Selene and Dr. Sakura saved the day.
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Next we will see Garp and Rosetta in action!