Soon, the group marked out a court right there in the training ground.
Or rather, they simply strung up a rope in the middle, without even drawing boundaries.
At this point, Sol had learned the special rules of tennis played in Hollow Special Operations Section 6.
The ball must not touch the ground—whichever side it landed on would lose.
He found the rule quite logical, specially designed for those with slightly superhuman abilities.
In an ordinary tennis match, the game was confined to a small court with countless rules, all because normal humans lacked overwhelming physical strength.
But for the members of Section 6, and for Sol himself, the intensity had to be a notch higher.
"The rules of Section 6 are truly extraordinary."
Sol weighed the tennis racket in his hand.
In shape, it looked identical to a normal racket, but its material was some kind of specialized steel.
The entire thing was solid metal, weighing nearly twenty pounds in his grip.
Forget tennis—if he carried it into a street fight, it would be a formidable weapon.
"Thanks for the praise." Tsukishiro Yanagi chuckled lightly. "Our old rackets couldn't endure much. These new ones are far better."
"That much is certainly true."
Sol couldn't help but laugh.
"Sol, you're our guest today, so you should serve first."
Tsukishiro Yanagi handed him a ball.
Sol caught it, his gaze sharpening.
Though only half the size of a fist, the ball weighed a full kilogram—dense and heavy in his palm. Its hardness surpassed even a lump of iron.
He glanced at the others' grips: Soukaku held her racket in both hands, as if it were her heavy war banner.
Hoshimi Miyabi gripped hers in a reverse single-handed hold, eyes sharp—as though she were wielding her katana, not a racket.
Beside her, Tsukishiro Yanagi gripped hers so firmly that it looked like she could split the sky in one swing.
Considering the steel rackets, this game of Section 6 tennis was bound to be… a little intense.
But the greater the intensity, the more Sol liked it!
"In that case, I won't hold back."
He decided to test the waters with a strike of one ton of force.
After all, Hoshimi Miyabi was the same girl who had pursued Nineveh with her blade, casually slicing past alloy gates along the way.
Even accounting for weapon assistance, her raw strength would likely rival his own.
With that thought, Sol tossed the ball high and swung his racket down.
The immense force sent the racket speeding like a giant fan, stirring up a gust that blew across Tsukishiro Yanagi's bangs, making her instinctively brush them aside.
The racket struck the steel ball dead on, producing a booming crack.
The reinforced ball shot forward like a cannon round, hurtling straight at Hoshimi Miyabi.
That one strike alone could have sent an ordinary man to the hospital ten times over.
Most people wouldn't even be able to react, let alone return it.
"The power is a bit lacking."
Hoshimi Miyabi shook her head slightly.
For her, this was still too weak.
Drawing into an iaijutsu stance, she raised her reverse-gripped racket from her hip in a swift, slashing motion.
It was a flawless sword-draw strike—so perfect that even Sol, a Martial Arts Grandmaster, wanted to give it a full score.
In an instant, her racket intercepted the incoming ball precisely.
Then, with tremendous force, she sent it flying back at double the speed it had come, hissing through the air with a shrill screech.
Tsukishiro Yanagi smiled faintly, stepping forward to meet the oncoming ball. "My turn, Sol."
It was mixed doubles, and properly her move.
She swung as though wielding a great cleaver, slamming the ball back with a crushing strike.
Sol called out in admiration.
No wonder she was rated 16+—every aspect of her form was excellent.
"Thanks for the praise. But Sol, don't hold back. Chief Hoshimi and little Soukaku are very strong."
Tsukishiro Yanagi's eyes curved into a smile.
And as her words reached him, Soukaku's lively voice rang out too: "Sol, Sol—watch the ball!"
Once again, the ball was returned with even greater force.
Standing just 1.5 meters tall, Soukaku swung her racket with both hands and unleashed a momentum worthy of a Gurren Lagann breakthrough.
"In that case, I'll play all out!"
Sol's eyes sharpened, his body tensing as he poured power into his arms.
Facing the incoming cannonball, the muscles of his arms swelled, veins standing taut.
Ten tons of force—equal to 130 horsepower—he unleashed in a full swing!
Compared to his first serve, the power had multiplied tenfold.
So immense was the force that even the steel racket warped under the strain.
Luckily, New Eridu had advanced far in new materials science, and the steel racket in his grip was a top-grade product.
It bent under pressure, then swiftly returned to form without shattering.
The ball shot off like a cruise missile, surpassing the speed of sound.
It tore through the air, leaving concentric sonic booms in its wake.
In the blink of an eye, it reached Hoshimi Miyabi, carrying with it immense heat from sheer friction.