Chapter 18:

Ch.2 – EP18 System Combat 56

Caïssa’s Child: The Boy Who Beat the AI

【Opening, Two Missing Pieces】

Heat shimmered up before Kyoto Pulse Plaza like a mirage.

The banner at the entrance—“National High School Chess Championship”—shone white and dazzling. The air in the venue was already taut with tournament tension, and local newspaper cameras ticked off shutters.

“…The two of them aren’t coming.”

Iori glanced at his wristwatch. 8:45.

“Where the heck are those two wanderin’ off to,” Sōma knit his brows. “Of all days, it had to be today.”

Akira silently hammered his phone. No new read marks.

“Round 1 starts at 9:00. If forty-five minutes of main time pass from the start, Sora automatically forfeits on time, but let’s at least complete check-in. We’ll say they’re in the restroom and wait until the last possible moment.” Iori decided and joined the line for team reps at reception.

Amid the human stream being swallowed by the venue, only their little formation looked like a hole.

(With two pieces missing, we can’t even form up a battle line—come fast. Sora, Momoko.)

—At that time—

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【A Black Car, Summer in Reverse】

The black sedan slid along a main road toward Kyoto Station—the opposite direction from Kyoto Pulse Plaza.

Outside the window, white sunlight flowed horizontally; cicadas’ voices were left outside the sealed space.

The two in the front seats spoke in low voices.

Man A: “We were ordered to bring only the kid Sora, right?”

Man B: “This girl wouldn’t let go of him, so we had no choice. It’d be a pain if she ran straight to the police… we’ll let the boss decide.”

In the center of the back seat, Momoko quietly regulated her breathing. Fingertips on her knees. Gaze lowered, reflecting only her own pupils in the mirror-finish door handle.

(—Don’t thrash. When you move, move once.)

Beside her Sora felt the throb at his temples ringing in his ears.

(…Calm down. A shape I can return to. Put my breath on four beats…)

But his lungs were cold; the beats slipped apart immediately. Sweat oozed into his clenched fists.

The car entered the underground parking of a mixed-use building near the station, and the temperature of the shade dropped a notch.

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【The “Office” as a Board】

The elevator opened. An inorganic office floor—yet the walls were hung with multiple model guns, giving off an uncanny sheen.

“UZI / MP5 / AR-15”—small plaques glinted.

Man A muttered over his shoulder.

“This is my first time at this office. These aren’t real, right?”

Man B: “The boss is a collector. They’re replicas. Interior decor. For intimidation.”

(Intimidation, huh.) With just her eyes, Momoko counted them. Weight suitable for use as a bat? Moving parts? —In the corner of her mind, her master’s voice sounded. Exit. Witness. Attention.

(We don’t need “attention” here. We need an exit.)

A glass door in back opened and a foreigner appeared. Pale eyes, a carrying voice.

“Well brought.”

He jerked his chin at the men, then cast a glance at Sora.

“Headquarters-designated ‘sample.’ No mistake. And—the girl?”

Man A: “She was with the sample and resisted, so we brought her along.”

The foreigner—who introduced himself as the head of the Japan branch—let his eyes halt on Momoko’s face.

In the depths of his irises, a warning light came on.

“You… Monika, aren’t you.”

The color of his voice changed. “Why did you bring someone so famous?”

Man A and Man B’s shoulders jumped in unison.

Momoko smiled faintly.

“Heh. Didn’t think I’d find someone who knows Monika in a place like this.”

Sora stepped forward one pace.

“Don’t drag Momoko into this!”

Man B reflexively reached out his arm. In that instant, Sora’s vision cut to white. Elbow, center of gravity, shoulder—lunge.

(Now I become the decoy. Momoko, exit—)

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【A Three-Move Tactical Skirmish】

“Stop—” Before the branch head could finish, the sound changed.

Momoko’s foot slid over the floor, flashing a strike to Man A’s groin.

“Gya—!”

Man A folded. The air wavered; a gap opened in their view.

At Man B, who was moving to grapple Sora—Momoko rammed him from behind, snaked an arm around him toward the stairs’ pipe handrail.

Using whatever was at hand, a joint lock; the cold of metal transferred to her palm. Enmesh / bind / flow.

“Sorry, could you go down first?”

In the next instant, pressure sank into his carotid, and Man B’s pupils rolled. Strength drained from his knees.

(Suffocation—close off the “airway” and people let go of the board, of consciousness.)

Sora turned.

(Momoko… strong. I—)

The tremor in his chest transmuted into a different heat.

“Both of you, stop!”

The branch head shouted and yanked a knife from a desk drawer. The dull silver bounced the light.

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【Knife Distance, Weapon Distance】

The branch head handled distance well. Half-steps in, in the rhythm of stabs.

Momoko barely avoided them, but the knife grazed her cheek and split the fabric at her sleeve. A pale line on white skin. A faint blood-scent rose.

(Head-on is a blunder. Change the angle.)

She planted weight on her rear foot to circle—and then the wall’s model guns caught her eye. Black, blocky, short-barreled. An UZI submachine gun.

Momoko grinned.

“Oh, that’s handy.”

“Hah?” The head sneered. “What are you gonna do with that toy?”

Momoko yanked the UZI model gun off the wall. A hefty balance landed in her hands.

Light grip, elbows tucked, wrist supple—a way to hold a gun for striking.

“Like this♡”

—Smack!

She struck his knife wrist with the barrel’s corner. Next, rapped his elbow with the butt end of the grip. Footwork in circles, arm arcs tracing curves.

Spinning through, she used the barrel like a tonfa to bludgeon / thrust / enmesh, driving the blade outward.

The knife clanged against the wall. The blade left the head’s hand.

“That way of handling a firearm… don’t tell me it’s Combat 56!? How does a little girl…?”

Momoko winked and gave a tiny shrug.

“You do know your stuff♡ It’s a martial art called System Combat 56. A neighborhood ‘uncle’ drilled it into me in Poland. Firearms aren’t just for shooting.”

Sora: “A neighborhood uncle…?”

(Note: System Combat 56—founded by Maj. Arkadiusz Kups of Poland’s 56th Special Battalion. A practical method treating firearms as multi-purpose weapons for bludgeoning / thrusting / leverage.)

The head retreated.

Momoko didn’t pursue a single step. She held distance and surveyed the board.

(Don’t rush the mate. Seal the escape squares one by one.)

The instant his shoulder brushed the wall where he was cornered—

Momoko slid the barrel to his throat and, using lever principles, targeted the airway to crush it.

The head’s eyes flew wide; there was the rasp of air.

On the third beat his consciousness drifted. On the fourth his knees buckled, and he blacked out.

“—Checkmate.”

Momoko exhaled lightly and slung the UZI over her shoulder.

On the floor, Man A was curled up writhing, Man B asleep quietly. The head leaned on the wall, eyes closed, chest rising and falling rhythmically.

The room’s clock pointed to 9:21.

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【Retreat Is Part of “Winning”】

“Okay, that’s—Szach-mat.”

Momoko winked with a peace sign.

“…Checkmate. In Polish.”

For an instant Sora was dumbstruck, then he gave a small laugh.

(Yep, best not to cross Momoko if I can help it.)

“Let’s go, Sora.”

Momoko looked at the wall fire alarm and decided not to press it. No attention right now.

Instead, she picked up Man B’s smartphone, popped the SIM, and plucked an employee card from Man A’s breast pocket.

“Exit.”

She said it briefly, opened the door, and took two corners down the hallway. Emergency stairs, emergency exit, underground parking—three egress lines layered.

Don’t use the elevator.

Pounding down the stairs, Sora regulated his breath.

“I’m okay… four beats… inhale and exhale…”

“Good work.” Momoko didn’t look back as she gave a thumbs-up.

At the parking exit they hailed a taxi.

The moment they slid into the back seat, Sora leaned forward.

“Driver, to Kyoto Pulse Plaza! Please hurry!”

In the rearview mirror, the driver took in the desperate looks on their faces and gave a short nod.

“Hold on tight. I’ll take the fastest route.”

The car burst up to the surface. This time the white blaze of summer poured in from ahead.

Catching the timing as red lights flipped to green, they slid into a narrow lane.

Behind them, an engine note rose as if giving chase—but soon faded away.

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【Breathing in the Car, A Declaration Off the Board】

“Can we make it?” Sora asked.

“We’ll make it,” Momoko answered at once. “Sensei(Elena) told you, right? If you won’t quit—win the championship. I’ll handle everything off the board for that.”

Sora looked out the window. Kyoto flowed backward at a steady speed.

In his chest, the cold of that black room still lingered. But another warmth overlaid it.

(Win with an explainable surprise. Quarters by classical beauty, semis by sharpness, the final—make them gasp.)

“…Momoko.”

“What?”

“Thank you.”

With that one word, the car grew just a little larger.

Momoko cast her gaze at the white roof visible in the distance outside the window.

“Save it for after you win.”

The car merged back onto the main road. In the distance, they could see the banner for Kyoto Pulse Plaza.

The time was 9:36.

“Nine minutes left.”