This is something a bit out of my usual comfort zone, but this'll be pretty fun for me to do none the less.

When the monsters resurfaced from centuries of being trapped underground, they were very surprised to see how much the world has changed. There were cars, very stall buildings, and technology that far surpassed what they had in the underground. The monsters were allowed to live in society like normal people. While some weren't quite as accepting, most of the other humans were fine with these monsters living in their neighborhoods.

In a very boring apartment there was a very boring looking man, in even more boring pajamas. This was our hero, Caped Baldy! The now B ranked hero was brushing his teeth, "Sensei! There are mysterious beingss in the new monster neighorhood of city Z!" Informed the cyborg. After the monsters moved into society, the Hero Association told the heroes to refer as the monsters as mysterious being, to avoid any negative assocaitions with monster kind, "well, let's go take care of it, I've been wanting to meet these new monsters, so whe might as well knock out two birds with one stone," sad the B class hero as he got in his hero suit in a matter of minutes.

Frisk was going to go to school whn a huge creature came and started terrorising the neighberhood, "holy shit that thhing's huges!" Yelled Undyne as she threw another spear at it,seemingly not doing any damge to it. The heroine then watched as a bald guy in a yellow hero costume, adorned with a white cape, red gloves and oots, and looked like something straight out of an anime, "who are you?" Asked the fish lady as the unknow stranger walked by, "I'm just a guy who's a hero for fun," answered the hero as he continued walking forward "wait, did he say for fun?" Thought Undyne as her jaw fel to the ground. The former captin of the royal guard watched as this stranger punch the creature with so much for, that it exploded into huge chunks.

Saitama looked at his fist as what just happened sink into his mind, "I'm back to one punchh again...?" This question was aimed towards anybody before he began screaming his lungs out,"DAMMIT!" Papyrus saw the entire thing from inside the hoouse, eyes spouted from his sockets, "woie, that human sure is strog, isnt he frisk?" Asked the skeleton. Frisk simply nodded as the hero stil screamed his heart out.

Well, there's that. Please give me any critque you can, so I may improve.