Twice the challenge, twice the reward

Shin was thrown off his feet and crashed into a wall of flesh. Right before the darkness took over all his vision, he caught a glimpse of a tiny form not unlike himself, and as he met Deku's palm, his right hand brushed against… another hand? A strange, warm tingle blushed inside him.

"I got you a surprise!" Kirishima blurted out as he removed his hand from Deku's. Before Deku, still in shock, could respond, he added: "Look in your hand!"
Deku was pale and motionless, his eyes fixed on his friend. "There w-was… there was a tiny man in there, Kirishima!"
"And now there are two!" The red hero grinned. "Come on, this is going to be fun!"
Deku sat up. The pain had not completely gone away, but it was tolerable now. He squinted at his palm. There was still Michat, his hair gushed undone, and next to him, laying flat on his face, another tiny man, taller by a head. He gently rolled the stranger on his back with a finger, and asked them if they were okay.

They both stood up and replied in unison: "Yeah, I'm fine." They looked at each other, surprised, and that sparkle inside made them blush again.
Shin introduced himself first, then Michat followed. Both heroes nodded in approval, but Deku was still intrigued by one thing.
"Shinsei, how come you're so small? Michat was turned small because of an accident, but you sound like that's your normal life..."
Kirishima didn't give his trainee a chance to answer. "It's because he's a Tiny, of course!"
"A—What?"
Shin sighed. "It's a long story, but that's not what we're here for today." He raised a clenched fist. "We're here to train and entertain!"
"We're here to ENTERTRAIN!" Kirishima yelled at the top of his lungs. Shin rolled his eyes, a little embarrassed at the pun. His trainer sure put the "boi" in "boisterous"... And his very revealing hero costume didn't help.
"You know what's great? We have two Tinies! They can be partners!"
The two "partners" glanced at each other for a second, then both looked away with embarrassment.
Deku smiled at them. "Don't be shy! You're both very nice people."
Shin coughed. "Yeah, I guess a friend of my friend's friend would be a friend... Michat, do you want to be my partner?"
The smaller man tried to utter something, then simply nodded. It was cute seeing him still in shock and awe, looking both frail and fierce.

Kirishima's oblivious words broke the silence like a punch of stone. "Today, Shin, you shall learn COOPERATION! Acting alone, especially at your size, could get you in a worse situation than you started from! That's why working in teams is so important: you combine your Quirks to plan a more complex and flexible strategy, and you can't get cornered! First on the list is: thinking quick!"

Without further ado, he picked both men from Deku's hand, and placed them at the top of each of his collarbones. "3, 2, 1, GO!" He flexed his arms, put his hands behind his head, and hardened his pecs.
It was like their world was shifting. The rather stable ground below them turned into a sharp slope, forcing them to slide down and collide at the top of the ditch between his literal rock-hard pecs. In his relaxed position, the gap was large enough that the two entangled trainees fell right inside.
Shin had to think quick. Kirishima said to cooperate, but they didn't know each other's quirk, and this was too risky a situation to act on his own. But what if...
He looked at Michat, and asked: "Did you watch...", but he knew he had to say no more. "One mind," he thought as they pressed their backs against each other's and dug their feet into the stone walls. They quickly wrapped their arms together and put out as much force as they could, until they slowed down and came to a rest very near the bottom of the gap. Far below were the valleys of abs, the unfathomably long pants and boots, and the hard tiles of the inhospitable floor.
They both took a long breath. "Ready to go?" Michat nodded again. "We'll start with right. Left. Right." They slowly climbed back to the top of the pecs, with great effort and great teamwork. There, Kirishima picked them up and let them rest in his slightly callused palm. "Not bad for a first try! You two look like you should be together!"
After an awkward silence, Deku spoke up. "How about you explain your Quirks so we can help you figure out how to combine them?"
"Sure!" Michat spoke first, for once. "Mine is Air Tunnel. I throw my hands in front of me, and it creates an air tunnel which transports me quickly in a straight line, until I hit a wall or a hard obstacle. It's mostly for running away from danger."
"Mine is Tiny Ballistics. I can shoot myself, much in the same way, except I have my fist forward brought to a point, making a force field around myself, so I can ricochet and pierce things. But I can only use it up to three times per day, then it has to recharge. It's more offensive, which is why I rarely use it."
"So they're both about quick movement," Deku muttered, "both offensive and defensive. Michat could clear a path and separate a group of villains his own size, or give Shinsei a speed boost, maybe even help him change his trajectory. Shinsei acts as a shield with his force field if Michat is behind him, while still dealing most of the blows. Maybe with enough training, their limits..."
Kirishima stopped Deku before he got lost again in his train of thought. "Training, yes! What we need is a good, safe training field full of obstacles for them to ricochet and slam into together! Any ideas?"
"Well..." Deku stared at Kirishima. "Is your hair gel strong enough?"

Michat tested the waters first. He looked at Shin, puffed his chest, and crashed straight into the tuft of hair in front of him. He took a couple steps back, a bit staggered. It hadn't moved at all. "Perfect!"
Shin and Michat put all of their remaining energy into flying and bumping through all parts of Kirishima's pointy hair. Shin could only afford to stop twice, because of his limited shots, and Michat, in support, only stopped when his partner did. They tried all sorts of combinations, helping each other go plus ultra past their limits, forming strategies, offensive and defensive maneuvers. It was a strange, almost alien feeling, being in someone's hair, especially Kirishima's which was sculpted like sharp mountains. When they became too tired to carry on, they both fell on their backs and stared up.
"It's like we're on Mars," Shin mentioned.
Michat chuckled in agreement. "You know what I like to do? Lay down in the grass, holding hands. It's very comforting."
"Well, at that size, it's an experience you definitely won't enjoy. Believe me, every stone hides something dangerous."

Kirishima stared at Deku. Laying down in the grass, eh? He could manage that for them. They had worked hard today. They were so cute together! They would make such a great team!
He winked at Deku, and Deku winked back. He gently fished them out with his thick fingers and smiled at them. "I'll see you both later!" He then placed them in Deku's soft green curls. That would be grassy enough, right?

Neither of them saw Kirishima leave the room. Deku's curls were like a field of blankets. It just felt right, resting in there. Well, almost right.
Shin reached out and held Michat's hand. "Partners," heh? Now it felt right.