Đại tiểu thư của Câu lạc bộ Tư vấn thích hỏi đến từng chiếc đinh và đinh tán!?

## Illustrations

## Deduction One ~ Treasure Hunts Are for After School ~

—Some things, for a person, really are “better not known.”

Ryugu Kotaro turned this thought over even as he ran down the academy corridor, already filling with the after-school rush.

—Damn it. What rotten luck. There’s no way I’ll make it.

Shoving through the other students in the hall, Kotaro clicked his tongue in fury. Against a mess this bad, he railed at time that would not wait.

It was nearly four in the afternoon. By now he ought to have been out the school gate and well on his way home.

—Faster. Faster. I have to get back.

Ignoring the stares around him, Kotaro took several steps in a single leap. He bit down on the tingling numbness that shot through both feet the instant he landed and sprinted straight for the building entrance.

He had a reason he absolutely had to get home quickly. No—more precisely, a reason he absolutely had to get off the academy grounds.

Ahead of him the entrance was already in sight. The finish line was right there. Change his shoes, run past the gate, and that would be enough. Do only that, and Kotaro’s insignificant wish would come true.

But.

“—Why the hurry, Ryugu-kun?”

He had only just seized the boots in his shoe locker when the wish died. At that familiar voice his neck creaked around like a rusted tin puppet. Toward the sound he wore the look of a boy who had known it all along, his face twisted and bitter.

Before his eyes stood a girl.

She was slight, her limbs long and slender, as if the lightest touch might snap them…

## Deduction Two ~ Demolition Requires a Brain ~

The fist that came down grazed his cheek, and Suzuhara Ikki felt the faint heat of skin scraping skin. He couldn’t help clicking his tongue.

“Damn it!”

Boiling over, Ikki shot out a hand, seized the person in front of him by the chest, and tried to throw him. The other fought just as hard not to give ground. Ikki was the bigger of the two, and strength was on his side. He caught the collar and yanked sideways.

Slam him into the wall of the house beside the road, and while he flinched, put a fist in his face. The judgment formed on its own, and Ikki drove the body toward the wall.

That was when it happened.

—Boom!

“…Huh?”

The sound left Ikki before he could stop it.

In the next instant, stone and rubble split apart with a tremendous crash.

Ikki stared at what lay before him and stood there blank. The man he had shoved groaned and toppled onto his back. His body rolled twice across the shattered concrete.

“—Hey, what was that noise?”

“A car crash?”

“Ah! Hey—hey! Look over there!”

Neighbors who had heard the bang came out to see. At the sight in front of them they broke into a clamor.

Ikki heard none of it. He only stood in a daze, shocked at what he himself had done, his face gone white, his whole body shaking.

Before his eyes, the concrete wall of the house had a hole in it, as if a vehicle had smashed straight through.

■■■

“…So that’s why you called me?”

Ryugu Kotaro held the phone to his ear. Once he had the gist of it, he let out a long sigh. In his heart he felt…

## Deduction Three ~ Who Made This Elementary Mistake? ~

Wood burned with a crackle and pop.

Black smoke rose above it and melted into the dark of deep night.

Moonlight and the streetlamps shone together with the ugly flame of the burning house.

Around the house a crowd of onlookers had gathered. Everyone chattered and guessed, as if they were watching a show at an amusement park.

“…Ah. Ahh.”

In front of the burning house a woman had gone weak in the legs and stared blankly as it burned. A man who might have been her husband was holding her up.

She kept watching, dazed, as the house burned—the house that was supposed to become their home in a few months. All she could manage now were shapeless groans, while the unfinished home went up in flame.

Far off, a fire engine’s siren sounded, as if mocking her.

■■■

After school at Manqiu Academy.

Fighting the heavy drowsiness that always came on after lunch, the students had at last finished their tangled lessons and, after a long battle, returned to freedom.

Some of them were sweating with gusto in the athletic clubs. Others, on the way home, were enjoying themselves with friends who shared their hobbies.

Ryugu Kotaro was one such boy.

The shouts of the sports clubs out on the field had become background music while he savored a cup of warm Japanese tea. He had put in a little extra leaf and was sunk in that rich fragrance, a small pleasure of his own.

This was Kotaro’s happiest hour.

“—I’m bored, Kotaro.”

A girl was making a nuisance of herself.

She…

## Deduction Four ~ Where Is the Blue Box of Happiness Now? ~

Slender fingers touched the firm soil.

Ten flawless, jade-white fingers dug at the earth and came away stained. In the silent dark, only the sound of one figure digging echoed.

“—Ha. Ha. Ha…”

The figure panted and kept digging, wholly absorbed.

At last the hands stopped. Those dirtied hands reached for the small box set beside the figure.

The figure took the box and lowered it carefully into the hole, stared at the little box lying in the pit, then began to fill the soil back in, gently.

Earth fell a little at a time. Watching the box slowly buried, the figure bit their lip.

They pressed flat the unnatural mound that stuck up, then brought both palms together over the spot.

—A deep hope that this box would never be found again.

So wishing, the figure stood a long while before the hole.

A shaft of moonlight fell, and a single tear slid down the figure’s cheek.

■■■

Manqiu Academy had a club called the Student Counseling Society.

In this hard modern age, students’ troubles came in every kind, and not every problem could be settled simply by talking it through with parents or teachers.

A student-led club for resolving those private worries—that was the Counseling Society.

It was something Manqiu Academy could take pride in: the students’ last resort.

And the two members who carried that important duty, known throughout the academy as a cut above the rest, were—

“…Ah. That’s good.”

“Right?”

They were idly drinking cold tea.

“The key is, with water and…