That morning, Luffy sat atop a large rock by a small river deep within the forest, an anatomy book borrowed from Makino open across his lap.
He didn't read it immediately. He simply stared at the pages he had already gone through countless times before—the diagrams of the human muscular system, the lines marking which muscle groups were engaged during certain movements.
Luffy traced one of those lines with the tip of his finger.
Muscles. Something inside the body that moved everything. Something that generated strength, maintained balance, protected organs, stored energy. And something that could be trained, strengthened… but still possessed limits for ordinary humans.
But he wasn't ordinary.
Luffy slowly closed the book and looked at his own hand. He stretched his fingers, letting the skin elongate slightly before snapping back. If normal muscles grew larger and harder through training, his wouldn't work that way. He had already learned that from years of experience. His body did not change like other people's bodies did.
But that didn't mean it didn't change at all.
Dense. Compressed. Elastic.
Like rubber that became higher quality the more it was used and tested. Not hard and rigid, but strong in a completely different way.
Luffy stood from the rock.
He looked up at the sky through the gaps in the leaves. The sun was already fairly high, its light falling in bright beams through the shadows of the trees. He raised one hand, letting the sunlight land on his palm before curling it into a fist.
"This is good weather," he said, "and a good time to start."
He slapped his palms together once, then began running toward the mountain slope.
The first month began with the simplest thing possible.
Running around the mountain every morning before the sun had fully risen. Not light jogging, but running at a constant pace without stopping until an entire circuit was completed. The slopes of Mount Colubo were not friendly terrain, filled with protruding roots, uneven rocks, and endless inclines, but that was exactly what Luffy wanted.
After the run, he would return to a flat area within the forest and begin with push-ups.
His method was unconventional. Luffy found two large stones heavy enough to use as weights, tied them to his back with rough rope, and started. The stones were so heavy that even on the first repetition, he could already feel the pressure crushing against his back. But he didn't stop.
After push-ups, he moved on to pull-ups.
A thick branch beside the river became his training bar. He tied two more large stones to his legs using the same rope, then began pulling himself upward. The weight was twice what it normally would have been. His arms trembled during the final repetitions, but he completed every set to the end.
Sit-ups with stones on his chest. Squats with stones on his back. Running in place with knees raised to waist level until the ground beneath him seemed to vibrate.
On the first day, Luffy could barely lift his arms when he returned to the hideout that night.
By the seventh day, it was already better.
By the twentieth day, he increased the weight.
And by the end of the first month, for the first time since those dreams had begun coming to him, Luffy was able to sleep soundly through the night without waking up with that uncomfortable feeling in his chest.
It wasn't something he had planned. It had simply happened. But it was enough to make him decide to continue.
There was one more thing he realized by the end of the first month.
None of the wild beasts in this forest were challenges anymore without him even needing to use his Devil Fruit powers. Wild boars that once required techniques to defeat could now be knocked down with a single bare-handed punch. Mountain bears he used to avoid, he now challenged directly as additional training.
Mount Colubo's forest was beginning to feel too small.
During the second month, Luffy started running faster.
Not merely faster in the ordinary sense. He began thinking about something different while sprinting between the trees—a way to create explosive bursts of speed instantly, movements that would leave opponents without time to react.
The idea came from something he vaguely remembered from childhood.
Garp chasing him.
Luffy couldn't remember exactly how old he had been back then, maybe eight or nine, and Garp had chased him across fields and village roads with a speed that made no sense for a man of his size. It wasn't ordinary running. There had been something different about the way Garp moved, as though tiny explosions occurred with every step, launching his body farther and faster than should have been possible.
As a child, Luffy hadn't understood what it was. He had simply run as fast as he could until he got caught.
But now he thought back on it.
He began experimenting. Trying to concentrate force into the soles of his feet before releasing it all at once in a single step. The first results were disastrous—too much force on the left side causing him to veer right and slam into a tree, too little force on the right making his movements uneven. He crashed into rocks, tripped over roots, and fell hard onto the ground multiple times.
But with every failed attempt, there was something slightly closer than before.
By the middle of the second month, his movements had begun directing themselves forward, though they were still rough and inconsistent. By the end of the second month, he managed to perform it with reasonable stability—kicking off the ground as many times as possible in less than a second, creating an explosive burst of speed in the direction he desired.
It wasn't perfect. It still drained far more energy than it should, and his directional control still needed major improvement.
But it worked.
In the third month, Luffy tried applying that stepping technique into his running.
The results were chaotic during the first week. Integrating a new technique into movements his body already performed automatically turned out to be much harder than using it from a stationary position. Several times he accelerated too quickly and lost control of his direction, crashing into trees, getting tangled in bushes, and once nearly plunging into a small ravine along the mountainside before his arm reflexively stretched out and grabbed a branch at the edge.
But with every failure came small adjustments.
Knees bent slightly more. Body weight leaning slightly farther forward. Slightly different timing on the step bursts.
By the third week, it was much more controlled. By the end of the third month, he could already sprint across rocky terrain at speeds that turned the trees beside him into blurs.
In the fourth month, another idea came to him.
Again, from memories of Garp.
Luffy remembered one occasion when Garp chased him and he tried escaping by climbing as high into a tree as possible, thinking Garp wouldn't bother climbing after him. But Garp hadn't climbed.
He jumped.
And in midair, instead of falling back down like he should have, his legs moved again, propelling him even higher, then higher still, until he reached Luffy's height and grabbed him effortlessly.
Back then, Luffy had simply thought it was another insane thing Garp could do.
But now he viewed it differently.
If stepping against the ground could generate explosive forward momentum… then stepping against the air—could it create upward propulsion?
Luffy began experimenting.
The results during the first few days consisted of a growing variety of falls from increasing heights. But his rubber body prevented serious injury, leaving only pain that quickly faded, and he would immediately climb back up to try again.
The fourth month passed with far more falling than success.
But during the fifth month, something shifted. The concept began to click—not kicking against empty air, but compressing and releasing force within his own legs, using his own body as the point of leverage.
At the end of the fifth month, for the first time, he succeeded.
One step in midair before gravity dragged him back down.
Only one step. Only around two seconds. And he fell immediately afterward.
But it was enough.
He stood on the ground after the fall, brushing dirt from his hair, and laughed.
In the sixth month, Luffy did not discover anything new.
He spent all his time refining what he already possessed. Running with the stepping technique until he could perform it without thinking. Air steps until he could sustain more than one step, though it still consumed tremendous stamina. Punches that combined the fundamental properties of his Devil Fruit with the physical strength he had built over the previous five months.
He found a massive boulder on the mountain slope, twice as tall as his body and three steps wide, and made it his punching target every single day.
During the first week of the sixth month, his punches left small cracks across its surface.
By the third week, those cracks had already spread through a quarter of its thickness.
And on the final day of the sixth month, with a single punch that combined his stepping burst and the full rotation of his body, the boulder split cleanly into two.
Luffy stood before the two dusty halves of stone, his breathing slightly heavier than usual, then slowly nodded to himself.
That evening after training, Luffy sat beside the same river as in the previous months, letting his feet soak in the cold water.
He looked at his hands.
Six months ago, they had looked exactly the same as they did now from the outside—fingers capable of stretching, elastic skin, no visible changes noticeable to the naked eye. But Luffy could feel it. Something beneath the surface was different now. Something denser, fuller, more prepared.
He lifted his arm and could see his muscles more clearly defined than before, even though they were not as bulky as those of people who trained normally. His arms had not grown dramatically larger, but there were sharper lines beneath the skin now, compressed and dense muscles, like ropes tightened to the perfect point—not overly rigid, but with no wasted space.
His shoulders were broader than they had been six months ago. His back was more defined. His legs, constantly used as the foundation of his new techniques, felt more solid whenever they touched the ground.
Not a body that looked terrifying from the outside.
But a body that was ready.
Makino had commented last week that he seemed taller than the last time he came down to the village. Luffy hadn't thought much about it back then. But now, as he looked at his reflection on the calm river surface, maybe she had been right. Not because of his training—he wasn't dumb enough to think push-ups could make someone taller. His body had simply grown in its own way, supported by the meat from his hunts that had never once run short over the past six months.
Luffy lay down on the grass beside the river, staring at the sky slowly changing color above him, thinking about something that had lingered in his mind for quite a while now.
How far was the distance between himself now and the truly strong people out there?
Garp visited Dadan's place every so often. Not too frequently, but not rarely either. And the next time his grandfather came, Luffy already knew what he wanted to do.
Not to win.
Just to know.
The river flowed quietly beside him, the sky above growing deeper orange, and Luffy closed his eyes while that thought continued slowly turning in his mind.