This story is a belated birthday gift for ineasako22, who wanted something adorable. Huge thanks to theherocomplex for helping with prompts when I got stuck. 3
"I don't think we should be down here, Leo."
Leonardo glanced over his shoulder at his little brother, who had hunched up against the wall so hard that his head was halfway into his shell. With a quiet sigh, Leo slipped his bokken through his belt and stepped over the trickle of stormwater that ran between them. Part of him knew Mikey was right. Sensei always told them when they asked that they were too little to go into the tunnels on their own. But that's why he hadn't asked this time.
"Mikey." Leo rested his hand against his brother's shoulder. "What does Sensei always say about getting better?"
Mikey stared at him for a moment before heaving a deep, exasperated sigh. "That we're not gonna do it without training."
"Right," Leo said, with a satisfied nod. "And Sensei would want us to get better, right?"
"I guess," Mikey said slowly, glancing over his shoulder. "But won't Donnie and Raph wanna get better too?"
Leo fought back the words he really wanted to say and patted Mikey's head. "They'll be fine, Mikey. This is our special bro time. Do you really want them here right now?"
Mikey perked up at that. "Well… no…"
"Great! That settles it!" Leo drew his bokken, gesturing with it like the warriors in Splinter's books. "Onward, faithful Mikey! We shall train to be great heroes!"
"Can I train to be a monkey?"
Leo turned to glare over his shoulder. "No. Monkeys aren't heroes."
"The Monkey King in that one story is," Mikey pointed out, rocking back on his heels.
Leo opened his mouth, but couldn't think of anything to say. Frowning, he stamped his foot impatiently. "You're not a monkey. You're a ninja. Let's go."
"Can I be a ninja monkey?"
"Did you say 'Mikey' or 'monkey'?"
"Will you just go!"
Some time later, the little trickle of water picked up speed, growing wider as other trickles joined it, and it wasn't long before Leo found what he was looking for. He stopped, planting his hands on his hips, letting out a small "oof" as Mikey bumped into his shell. Grabbing on to Leo's shell, Mikey peered around him at the complex tangle of pipes and walkways that criss-crossed the junction before them.
"Oooh," Mikey said softly.
"The perfect training place," Leo said.
Mikey squeezed between Leo and the tunnel wall. "Leo, are you sure-"
"Yes," Leo snapped impatiently. "Now come on. Time for training!"
Pushing past his brother, Leo eyed the walkway across from them. He took one step back to give himself room for a running start, kicked off, and leaped.
The moment in the air when you stopped going up but hadn't quite started to come down was always the most fun, but also the scariest. Leo always held his breath at that part, as his stomach flipped over and his head started to spin. But before he had a chance to get too scared, his feet were on the grate of the walkway, echoing throughout the junction with a clang.
"Ha!" he said, turning to Mikey. "Beat-"
But Mikey was already beside him, beaming. "My turn!" Whooping with glee, Mikey flung himself to the walkway below. "Come on, Leo!"
Leo inched slowly toward the edge of the walk he was on, peering down at Mikey. The other walkway was an awfully long way down…
Training Leo. Think of your training.
Clenching his teeth, Leo leaped, falling through the air toward his brother.
The raced through the sewers, leaping and dodging as they chased each other through the maze of tunnels. Every so often, they came together long enough to exchange a kick or a punch, but most of it was chasing. Endless chasing, across culverts, and pipes, and walkways, making their way around to the junction again and again.
Leo always forgot how hard it was, but even when his legs began shaking, he refused to give up. Training was important. Training was the only way to get-
He missed it. Between one breath and another, his toe grazed against the pipe he was aiming for, and with a soft cry, he plunged into the dark.
His breath coming sharp and fast, he scrabbled for a grip on something, anything, but though his fingertips brushed against a pipe or two, it was never enough to let him get a good grip. And so he fell, helpless to do anything but watch as the green blur above him leaped gracefully from pipe to pipe like the monkey he'd envied, drawing ever closer to Leo as he fell.
Mikey's hand locked around Leo's wrist and he stopped with a jerk, swinging back and forth before Mikey let go, and Leo dropped the remaining few feet into the mud puddle below him. He lay, groaning, as Mikey swung upside-down from the pipe overhead.
Mikey folded his arms across his plastron. "Y'know what I think, Leo?"
Leo moaned and wiped the mud from his face. "What, Mikey?"
"I think you didn't want Raph and Donnie here because you're already embarrassed that I'm better at Two Lines than you, and you didn't want them to be better, too."
Leo closed his eyes and draped his arm across his face. If there was one thing he hated, more than anything else, it was when Mikey was right about stuff like this. It drove him nuts that he needed to get training from his little brother on anything, let alone ninja stuff.
But then, he wouldn't have had anyone else with him, either. No matter what happened, he knew that Mikey wouldn't let him fall.
A squelch in the mud next to him told him that Mikey had gotten bored with swinging, and he grunted as Mikey flopped across his plastron. "Hey Leo?"
"I make a pretty good monkey, huh?"
Leo smiled, and lowered his arm to rub Mikey's head. "You make the best monkey. Just…" He bit his lip. "Don't tell Raph?"
"Pfff." Mikey poked Leo under his arm. "'Course not. Then he'd want training too. And this is our bro time." He rolled over, resting his chin on Leo's plastron. "Right?"
Leo's smile widened, and he dragged Mikey up so that he could hug him properly. "Right. Secret training is just for us." But as he squeezed Mikey tight, he couldn't help but notice the squish, and he looked down with a wince. "But we should probably go wash up before Sensei finds us. This mud is pretty bad."
"I'm a mudpuppy!" Mikey said, leaping to his feet. "I shall never be clean!" A gleam shone in his eyes as he shifted away from Leo. "Not unless you catch me!"
And with that, he was gone, jumping into the pipes overhead.
Leo stared for a moment with his mouth open before he followed, but he couldn't be mad. He should have expected that. When it came to Two Lines, Mikey was a training master. Leo could only follow, and hope that Mikey didn't push him too hard.
Last time, he'd been bruised for a week.