A/N: Well, I watched all of O.K. K.O. in about six hours, got a little obsessed, and made a fanfic of it! The whole power level thing reminded me of a certain hero who's probably topping the scale. Welp, please enjoy this oneshot.

~*Q*~

K.O. was happily mopping the floor of Gar's Bodega when a bald customer with a cape walked in. Automatically, he looked up with a smile.

"Welcome, sir! How may I help yyyyyyy-"

His jaw dropped. His eyes widened. His hands spazzed into the air of their own accord, sending the mop flying.

He stared goggle-eyed as the customer ambled into the store, heading towards the ready-made foods aisle, unaware that his "you" was still dribbling out of his mouth, unfinished.

Just as the bald guy rounded the what corner, K.O. found his voice.

"YYYYYYYOU'RE MR. SAITAMA!" he screeched, causing every single head in the store to whip up...except for the caped man's in question.

K.O. raced after him, sliding for a good ten feet on the ultra-polished floor.

"Oh my gosh!" he hollered, startling Saitama, who was reading the label on a can of noodle soup. "I can't believe it's really you! Saitama! In Mr. Gar's store! This is such an honor! No, this is the greatest day of my life!"

He jumped up and hung on Saitama's arm, trying to shake it enthusiastically, but he just ended up hanging off of it and swinging gently. Then, as if he was soiling a sacred artifact, he let go and crashed to the floor.

Saitama put his can of soup down, completely nonplussed. "...Do I...know you?"

Rad, who'd went looking for K.O. as soon as he heard the noise, came rounding the corner. "Hey! What's all this?" He glared at Saitama, then at K.O., who was alternately hopping around, clutching his head as if it were about to explode, and scooting around on the ground like an inchworm.

"Rad! Rad!" K.O. bounced over to him, pointing excitedly at Saitama. "He's a hero!"

"Hey, so am I!"

"No! I mean!" K.O. gasped for words. "He's the strongest hero!"

"How do you know that?" Saitama asked, confused.

"Yeah," Rad added skeptically. "I mean, Mr. Gar is pretty strong. This guy doesn't look all that tough. What's his level?"

"Nobody knows!" K.O. said dramatically.

"It's not on his POW card?"

"I don't have it!" K.O. said, and Rad mimed an expression of shock at the thought of K.O. missing a card in his precious collection. "Neither does Dendy. I don't know anybody who does. It's really rare. Mr. Saitama!" He wheeled on the superhero, who'd been edging away, picking up more cans of soup. "Don't you have your POW card on you?"

"What?" Saitama rubbed his ear, looking uncomfortable. "Nah… where I'm from, we don't carry our cards around, you know?"

"Of course! I-I'm sorry!" But K.O. kept tagging along with the hero as Saitama continued to browse the shelves. Rad followed from a distance, equal parts annoyed and intrigued.

"My name's K.O.!" K.O. was saying, keeping up a constant stream of chatter. "Would you like to be called Mr. Saitama? Or Saitama-san? Or Caped Baldy? Or-"

"Saitama's okay," he interrupted.

"Is it really, really true that you can beat anything with one punch?"

"Where'd you hear that?"

"Internet."

"Ah."

"Woooow," K.O. whispered to himself. "A real, live, triple-digit mega-strong undefeatable hero."

Saitama scratched his bald head, then his arm, awkwardly not making eye contact with K.O. He wasn't used to being recognized, especially not as an unbeatable hero, and especially not by someone who was quite literally mopping up the dust before his footsteps and was now dashing over to a bored-looking cashier to chase her off her phone.

"Come on, Enid!" he whispered while Saitama set his purchases on the counter. "This customer's special! I promise!"

Enid glanced up, gave Saitama a look of slow and utter distaste, and began to ring up his items with the hand not occupied by her device. From behind K.O., Rad shot Enid fingers guns and slid off to go pretend-to-work somewhere else.

Saitama stood patiently. He noticed that K.O. was sidling up next to him again.

"Soooo….." the boy said. "Got any tips for leveling up?"

"No."

"R-Really? None at all?"

"No."

"That'll be 12.46," Enid droned.

"Hey," K.O. said in a soft, pleading tone, "you can trust me! I want to be a great hero and I need to level up as fast as I can! Surely you know some kind of wisdom you could pass down?"

"Do you take this?" asked Saitama, placing a bag of yen on the counter. Enid groaned for a solid five seconds and started counting it, doing the conversion her head.

"Mr. Saitama-" K.O. started.

"Hey, look, kid." Saitama turned to face K.O., who snapped to attention. "I'm just a guy who's a hero for fun, all right? I don't have any advice for you. Being a hero...it's not all it's cracked up to be."

K.O. stared at him, bewildered.

He sighed. "Anyways." He picked up his soup cans and turned to leave.

But he only got two steps before an alarm pierced the air and a rumble shook the building. K.O., Enid, and Rad (diving into view from behind a stack of crates) immediately dashed outside to assess the problem. Okay, well, they knew the problem was Lord Boxman. They just wanted to see how long they could afford to laugh at his latest robot before it started looking like something of a threat.

But when this box dramatically fell from the sky, it opened up to reveal….a Jethro. Everybody groaned, even K.O., who'd gotten used to fighting them and was over the "existentially relating to a robot" thing.

"I AM JETHRO!" Jethro bleated.

Enid immediately teleported back to her station at the register, leaving her customary stump in its place.

Rad sighed. "Well, K.O., just go ahead and meet us inside when you're done."

"All righty!" said K.O., trying to muster some determination. Saitama was still in the store, maybe even watching, after all.

Rad went inside. K.O. reeled up for the biggest, flashiest punch he had and hit Jethro square in the face. The robot crumbled.

And then….it revealed a pile of scraps within itself that built themselves up into another Jethro, bigger than the first. The new Jethro starting rolling forward at the exact same pace as the first. Not exactly comprehending the difference, K.O. punched it again, sending the robot flying backwards - and reformed after only a couple seconds. This time K.O. definitely noticed that this Jethro was almost twice as big as the first. "What the...how's it doing that?"

He destroyed the Jethro several more times, knocking it back over and over again, but it kept on getting bigger. When K.O. realized that the last punch had really hurt his hand, the problem dawned on him. Not only was it getting bigger, it was getting tougher and tougher to defeat.

K.O. gave the next Jethro a good kick; it crashed end over end before crumbling halfway across the parking lot. That gave K.O. time to run back inside and warn Rad and Enid. He streaked into the store already yelling their names.

Saitama had been held up by Enid, who was counting out his change in technos, but he looked baffled when K.O. reached the counter, fell flat on his face, and jumped up again, sputtering. "J-Jethro!"

"Jethro?"

"I AM JETHRO!" Jethro blared from outside...much, much louder than before.

Enid took one look out the window, where Jethro was level with the roof of the store, and stuffed her phone in her pocket. "Okay, just...go get Rad. Boxman pulled this on us a few months ago, we just need to stall it until Mr. Gar gets back."

"But...he's not coming back for hours! He said!"

"Fine, whatever! Just get Rad!"

"Already on it!" Rad raced past her, levitating a bunch of cans, and hurled them at Jethro. They crunched into him, leaving deep dents all over his face. K.O. ran to the window while Enid and Rad started to kick Jethro into submission.

"...is this a problem?" Saitama asked nobody in particular. He was still clutching his merchandise.

"Oh, no, no, no!" K.O. said hastily. "We just get some evil robots about here every so often -" Another bellow of "I AM JETHRO!" shook the building as Jethro reassembled himself. Enid and Rad were climbing all over him like monkeys, trying to stop his pieces from reforming. "It's not usually a problem. Really."

The giant robot towered over Lakewood Turbo Plaza. Enid and Rad hacked away at it, but it had grown so strong that Enid's fireballs were the only thing leaving a scratch. It would steamroller over the store before Enid could do nearly enough damage.

"...maybe a little problem," K.O. said. "Hey! Mr. Saitama! You can help us!"

"What, me?"

"You're a hero, right?"

"This is…." Saitama didn't know how to explain that the problems he usually dealt with were a little more high stakes than a badly-built robot trying to crush a tiny bodega. Anything else was mind-numbingly easy, the sort of thing he left for Mumen Rider.

"Come on!" K.O. pleaded. "What's the good of being a hero if you don't help anyone who needs it?"

Good point.

"...All right," Saitama relented, allowing himself to be pulled outside by K.O.

Meanwhile, Enid and Rad had been desperately trying to keep the robot away from the store. Rad saw no sign of a simple on/off lever inside of Jethro's head, and Enid was out of fireballs. They were pushing the robot back by sheer force.

"K.O.!" Rad yelled when the kid rushed over to them. "Any sign of Mr. Gar?"

"No, but I've got someone just as good!" K.O. raised Saitama's hand.

"The customer? The guy with no POW card or whatever?"

"Yeah, him!"

"What are you guys on about!" screamed Enid as she dug her heels into the ground.

"Okay okay okay!" K.O. hopped around excitedly. Despite the situation, he was looking forward to seeing a cool mystery hero in action.

Saitama stood in front of the robot. He held out his hand. Jethro groaned to a stop, rolling forward uselessly, as it strained against his might, but Saitama didn't budge an inch.

"Wooooow!" K.O. whispered as Enid nodded approvingly.

Saitama raised his hand. That was all it would take. Just one punch. Not even a simple punch; it'd be like knocking on a door. But as he raised his hand, the flood came back: the years of waiting for a better opponent, the training, the hair falling out, and above all, the sheer, mind-bending, soul-crushing boredom.

He started to relax his hands. He wanted to help the kid, really, but he muscles were freezing up, reacting against the thought of going back to that life.

"Saitama?" K.O. questioned. as the robot started rolling again.

The robot was making a horrible grinding noise as it pushed Saitama backward into the store.

"Wait, but -"

"HEY YOU!" Rad shouted over the din. "IF THE ROBOT ROLLS OVER THE STORE, YOUR SOUP IS GONNA GET SQUASHED FLAT!"

He took a deep breath.

"NO REFUNDS!"

Saitama's hand blurred forward and gave Jethro...a light tap. The robot exploded. Every single piece it was made of disintegrated into a paste of fine metal that blew away in the wind. There was nothing left of Jethro.

The silence was broken by K.O.'s cheering. "You did it! Awesome!"

Rad and Enid stared, openmouthed. Saitama looked down at his hand. Why had he hesitated there? He wasn't that far removed from saving a little kid's store, was he? Just because he didn't think it was challenging enough…? That sort of thinking was only a step removed from Lord Boros. He let out a sigh. Man, he needed a break.

He was interrupted by K.O., who was tugging on his hand again. "Hey, Mr. Saitama! Thanks so much! Free lightning nachos for saving the store!"

"...thanks."

"Oh, before you go-" K.O. zipped after Saitama as he went back inside to retrieve his purchases. "Before you go, won't you get a scan at the POW machine in the back? Please? Just for fun?"

Saitama looked at the kid's eager face. "Fine, fine."

Five minutes later, Saitama, munching chips, stood in front of the machine waiting for his result. The slot spat out his POW card. K.O. turned it over to get a look. "Let's see, your level is….HUH?!"

INFINITY?!

~*Q*~

A/N: I haven't watched OPM in a while, but I tried to keep everyone as in-character as possible. Have a great day!