Unsuccessful Experiment

Kuro saw Okayu swimming at the small rivers really happy as an strange and ridiculous idea spouted up inside his head.

The reasonings of this ridiculous idea was the ripples in water. Ripples preading from Okayu's every movement—and to the water that splashed to the air which returned once again to the ponds, caused a ripple as well.

The point is, the ripple caused by the droplets were spreads smaller than the ripples Okayu caused.

So looking at this ripples this thoughts appeared in Kuro's head: Can I copy Gura Gura Fruit from what I've heard from 21?

The Gura Gura Fruit, according to 21, it seems to be able to cause an earthquake and is said to be able to destroy world.

It's power is to cause an vibrations or a shockwave which can travel to the ground, to the water, even to the air which is said to be the reason.

Ain't that similar to the demons' technique? To control the force accurately.

Comparing the two, Kuro was even more sure. He was sure that even if he can't do it, that guy: Nakiri Soujin should be able to do it.

To test this idea, Kuro's took his hand from the water which was submerged. Then gripped it hardly.

"Kuro..? What are you doing." Rather than her water play, Okayu' attention went to Kuro for a reason.

With her Ki Sense, she spotted Kuro controlling the force to make a sphere in his hand—copying Whitebeard.

And he condensed the force as he gripped harder and harder while the sphere increased its size. This was an incredible demonstration of his control over the force.

Instead of the pressure stored inside that tiny hand of his, the force is outside, making an invisible spheres.

This meant that there's no pressure inside Kuro's hand even though he's gripping tightly. For example: even if he was gripping tightly Okayu's hand, she would feel no pain—the result is the same even if the hand he is gripping is the ordinary person's.

'Is this enough?' Unsure, but this was the best force he could unleash and control. The force inside the sphere was about to pop like a bubble but before that, Kuro smashed his fist downward with all his might.

*Pop*

An strange sounds travelled the air as the sphere in Kuro's hand exploded inside the water. In contrast of his expectation to produce vibrancy inside the water to cause an small tsunami, the sphere exploded.

Making the water to travel downward while the upper part of water to fly high up the air—at first sight, this may be a normal effect because Kuro smacked his hand downward so it's not unexpected for the water to splash.

But Okayu who had Ki Sense and was taking a bath with Kuro, knew it. Despite they being so far away, she felt the water push her slightly.

From her eyes, she saw the force Kuro's sphere push away the water all around.

Despite failing to achieve the effect of tremor by producing massive vibrancy, he unexpectedly created a bomb.

'Wait, all around!?' At this moment, Okayu noticed something terrifying as her eyes changed to serious—her carefree expression being long since gone.

"Kuro! Are you okay!?" Kuro tried to hide it, but Okayu grabbed Kuro's arm from wrist carefully. It was badly damaged.

His arm being the center of force explosions, took the most damage. This experiment being successful at the same time, unsuccessful.

"Haha. Another self-harming technique produced! This time, it's an charge attack. Isn't it impressive, Okayu-chan?" Reading Okayu's expression from her eyes, he nervously tried to joke to make her smile.

"Don't use that thing again! Okay!?" She angrily scolded Kuro after ignoring him. Her gaze never leaving from Kuro's battered hand.

"What're Okayu-sama saying? As long as my body get tougher…"

"Okay!?" Okayu didn't give Kuro a chance to finish his sentence and continued with her last word.

"O-okay…" Kuro weakly gave in.

"Pinky promise!" While being half-angry and half-sad, she brought her pinky from the water and looked at Kuro's other hand.

Seeing that she's not going to give in, Kuro brought his other hand as the two pinky fingers intertwined together.

"Pinky promise! Pinky promise! If Kuro used this technique again, Kuro will be stabbed with thousand needl… that's scary! If Kuro used this technique again, Kuro will be scolded by me!"

The attitude change were too big for Kuro to remain calm as Okayu continued her chant and after that, both of them released their hold.

"Hehe~… Kuro~♡ how did you do that? Teach me~!" The seriousness were gone while she went back to her usual mood.

"What!? Didn't you just say that I am not allowed to use it?"

"Not allowed to use and to teach is big different! Teach me or I'll tell Ayame-chan that you used an strange self-harming technique again!"

Okayu was talking about the control of force to make his speed almost twice as fast, one which Maou also pointed out.

When Ayame find it out, she scolded Kuro greatly. From that on, he told himself that he'll only use it when absolute necessary.

Also, the scolding Oni were a very scary Oni. It almost became his trauma.

"No, no! Nothing but that! I will teach you! Like this, drag the force into your hand…" Kuro panicked like a child who did something wrong.

Looking at this Kuro, Okayu suppressed her laughter and she calmly looked at Kuro with that carefree expressions of her.

"Nya~. (I will protect you)"

She didn't want to lose anyone again…