This is my first fanfiction so any advice would be appreciated in the comments. I am trying to keep the characters similar to their characteristics in the manga, but if I don't do the best job it is only so that I can make certain plots work within the story. This will probably be a Tatsumaki/Saitama pairing, but I won't be doing anything with it for a while until my writing skills improve.

Chapter 1

An Enemy is Born

Saitama entered his apartment and slammed the door behind him. A slight roaring sound could be heard as the door ripped off its hinges and slammed into the side of a building across the street. 'Shit…not again' Saitama thought. This ended up happening almost any time he practiced his serious series moves or any of his advanced moves above the serious series. Of course, he never actually practiced them all out. For many of the moves he could only go through the motions of the moves unless he wanted everyone within the surrounding cities to notice. The fact remained though, that just practicing the moves would throw off his rather decent control for the remainder of the day.

Keeping a low profile for now was one of his main priorities. The reason was simple; it was quite annoying to deal with a mass amount of people who would offer up no thrill of a fight. He knew the Hero Association had no one who could match him….at least to his knowledge. Furthermore, even with his dull observation skills he could tell that not everyone in the association valued the true meaning of a hero. Having everyone intervene with his shopping and daily routines would be quite the hassle as well.

It was for this reason that Saitama had ditched his original costume and gone with a black cloak inscribed with red kanjis that read 'One'. On the backside a white cape with symbols for all of the cities A-Z were inscribed. He had even installed a secret pouch on it to keep his weekend sale coupons in so that he wouldn't need to return to the house. Too many times had he been distracted and missed his weekend shopping while fighting a monster. It was one of the few things that actually made him angry and it was during one of these times that he first discovered his serious move set. Due to the fact that the end result was a new volcano being created in the wastelands outside of City K he had decided to never carelessly use any of those moves around other people or even other heroes.

At first it was near impossible for him to keep his costume in a non tattered state. Eventually, this problem was solved when Saitama realized he could send a type of aura into objects in contact with him. This only worked very close to his skin though, so his cape would still get destroyed somewhat regularly. Asides from adding a defense to his costume this ability seemed to have no other useful benefits and through experimentation he found that this aura could not be applied to animate objects.

There had been no good monsters today as usual. All of them had been destroyed in one punch. Asides from practicing his serious moves nothing had happened today. He disappointedly threw his uniform into the corner of the room and flicked on the television.

"And today in city C a mysterious being containing powers blatantly destroyed several monsters and openly declared war on the Hero Association," blurted the news announcer as the camera panned to an overhead shot of City C.

Saitama furrowed his brow a bit. 'Hmm City C that sounds pretty familiar….I think I may have been there today, but I'm not really sure.' The broadcast then quickly cut to a picture of a man in a black cape. 'Well damn, I guess I got pretty careless today. Then again, when am I actually paying attention to details?...'

The news announcer continued, "This man was at the scene when he struck down two C class heroes; the Bug Duo. The C class heroes were dealing with an evil bug swarm when the cloaked man attacked them destroying the bugs in the process. The two are in critical condition and it is reported that they most certainly would have died if the man attacked them directly. The cloaked man is currently being listed as a low Tiger rank threat by the Association. Due to the fact that he has the logos of all the cities on his back we can only assume that he means to target and demolish all of them. Due to his unknown power he has not been ranked higher. His current codename is Faceless as we have no clear cut details about this person. All these details were caught by our news helicopter".

'Ahh…so that's what those buzzing sounds were. I assumed it was a fly. Well, I guess it was only a matter of time until I was discovered. Regardless, I already have the perfect setup for this situation. I will have to be much more careful about my work habits though. At least they didn't name me something dumb like Caped Hoody though. I do feel sort of bad about those heroes though…why the hell were they dressed up exactly like the enemy; do they want to get killed?' He flicked off the T.V. and with a sigh retreated to his bedroom for some rest.

'WHAM' As he woke up to his blaring alarm Saitama was quick to realize that his head was currently residing in the ceiling of his bedroom. If he was a normal person he may have made an exclamation of pain. Instead, he removed his head from the hole and proceeded to the kitchen for his breakfast. A few minutes later he left his house and caught a bus to his job. As the bus crossed the city he could see his destination looming as a giant rectangle appeared on the horizon. Saitama worked as a janitor at the Hero Association.

Although most of the time heroes were not at the Association building they would still lounge around as they liked being in the company of other strong individuals. Saitama could only access the lower levels, as it would be foolish and unreasonable of the Association to allow a lowly janitor to any area that may contain restricted information. Saitama was still able to get tidbits of information that were valuable to his assessment of other heroes however.

For the most part many ignored him except for a few individuals. Speaking of one of these individuals….'CLANG'!

"Well are you going to clean this up or not", complained a green headed girl while she pointed at the bowl of food on the ground that had been purposefully knocked onto the ground.

Tatsumaki, rank number 2 of the association, and in Saitama's opinion rank number 1 in annoyingness. He had to admit though, that he would also rank her very high on an attractiveness scale. 'If I didn't need this info right now I would completely ignore this brat' he thought. Instead he ground out a "Yes Tatsumaki" as he began to clean up the oatmeal on the ground.

"Did I say you could call me by my name janitor?" Tatsumaki said with a smug look on her face.

At this point Saitama was actually starting to get a bit riled up and replied with a "Sorry". It wouldn't do any good for him to get Tatsumaki mad. If she used her psychic powers on him and he got away without a scratch the game would be up.

Tatsumaki was bothered by those who were below her. 'I guess I can tolerate the other heroes; they at least have strength to back themselves up.' People like the janitor annoyed her however. The fact that someone of his class was able to associate with heroes was disgusting. Furthermore, she was riled up about the new assignment that was given to her. She glanced down at the paper in her hand that had a single word written at the top, 'Faceless'.