168 If the reasoning is correct, then there can only be one truth
"I, Rurichou Nadeshiko, absolutely will not allow anyone to defile the sanctity of sound!"
"The one who masters sound and weight shall claim victory in [The Worth of Sound is a Thousand Gold]! Hikigaya Hachiman, do you have the resolve to challenge this?!"
Resolve?
Hikigaya played with the coin in his hand, an amused expression on his face.
The word "resolve" could only be associated with women like Yumeko or Kirari — a clash of pure madness.
But for someone calculating like Rurichou Nadeshiko, the so-called "resolve" was just a cover — a way to deceive others.
She might understand gambling well, but Hikigaya understood people even better.
The elegant, piano-playing girl before him wasn't as innocent as she appeared. She looked like a refined young lady, but behind the scenes, she was involved in secret filming and blackmail. She seemed noble and graceful, yet wore cute teddy bear underwear.
A deeply hidden contradiction.
Having analyzed her persona, it was now easy to deduce what kind of cheating methods she might employ.
'Rurichou Nadeshiko — she acts like she holds sound as sacred, but she doesn't actually revere it much at all.'
'This gamble likely has nothing to do with sound... it's just a smokescreen.'
Hikigaya was utterly convinced. Judging the number of coins by the sound of them colliding? Don't make him laugh. Even someone like him, with superhuman analytical skills, couldn't do that.
Or rather, it simply wasn't something a human could do.
Just like in Agatha Christie's The ABC Murders, where an apparently random string of killings concealed a single true target, everything else was mere distraction. Rurichou Nadeshiko's measurements were likely the same.
Sound? Weight? Both were likely red herrings.
She was probably relying on something that bypassed those two key factors entirely — a decisive trick that determined the outcome of the gamble directly.
'What could it be?'
Hikigaya carefully observed Rurichou Nadeshiko.
'Hairclip, necklace, watch...'
'Could it be that?'
Hikigaya's eyes gleamed. The clues were still too few; he couldn't yet confirm whether his deduction was correct.
"In that case, let's kick off the first round with 1 million yen to test the waters." He said casually.
1 million yen?!
Rurichou Nadeshiko involuntarily took a sharper breath. She had always wanted to earn enough money on her own to buy a Steinway piano. Only a piano like that could be worthy of her music.
Kurume hadn't lied to her — Hikigaya Hachiman really was a dumb, rich fat sheep!
'With this, my Steinway piano will soon be mine.'
Hikigaya did make one mistake in his analysis.
That was — while Rurichou Nadeshiko didn't revere sound, she truly loved sound. To obtain the most beautiful musical tones, she would do anything, no matter how despicable.
Whether it was blackmail through secret photography or cheating in gambling, to her, it was just a means to an end.
Although her photo scheme had failed and she was furious at the lost money, as the saying goes — when God closes a window, He opens a door.
The money she lost by accident, she was going to earn it all back today!
"Then let's go, Hikigaya-kun."
The two sat down, each reaching out to take a piggy bank.
Hikigaya casually grabbed a handful of coins, glanced at them, then tossed them into his piggy bank. The crisp sound of metal clinking echoed in the empty music room.
Once all the coins were in, he placed the piggy bank onto the balance scale.
"You're surprisingly decisive, Hikigaya-kun. But too bad, I've already heard it~ Your sound." Rurichou Nadeshiko tapped her ear with a smug look, then mimicked Hikigaya's actions and picked up a few coins.
However, the speed at which she dropped the coins into her piggy bank was noticeably slower — she didn't finish until the ten seconds were up.
Hikigaya noticed this detail. She seemed to be deliberately stalling.
The balance scale — was level!
Hikigaya's eyes narrowed. As he observed Rurichou's movements, he began rapidly calculating in his mind.
He had bet a million yen in the first round in order to catch her off guard and expose a flaw. If the wager was too small, she might not even bother to cheat.
'I tossed in nine 1-yen coins and nine 50-yen coins. If Rurichou Nadeshiko matched my total...'
'That's 45 grams in total, which has 11 possible combinations.'
'Given the sound element, the extreme values can be ruled out — that leaves six plausible options.'
"36 coins."
Rurichou Nadeshiko's voice interrupted Hikigaya's train of thought — she had given her answer.
Rurichou's logic was simple.
If he was just a fat sheep, it didn't matter how she bled him. Strike while he was unaware and his gambling spirit still burned — drain all his money in one go!
Kurume beside her was surprised: "Eh? You're locking in already? Not gonna think it over, Nadeshiko?"
"No need~ Because my ears already heard the answer~" Rurichou replied confidently. "Kurume, please check both our piggy banks."
"Alright then."
Hikigaya gave a deep look to the smug girl in front of him — that proud expression… showed no sign of guile.
"You got it right! Nadeshiko, there really are 36 coins inside!"
Kurume exclaimed in surprise, dumping the contents of the piggy banks in front of them: "No need to count — both sides have the same number."
"Yay!"
Hikigaya keenly noticed a flash of relief in Rurichou's eyes.
That meant — she didn't know the exact number of coins. With the weight being equal, she could only make an educated guess within a certain range. In other words, for this round, she had roughly the same amount of information as he did.
36 coins — that had been within Hikigaya's expected range too. He had just hoped to gain more intel and guess correctly within the "1 out of 6" chance. He hadn't expected her to beat him to the punch.
'This round was my loss. Hesitation leads to defeat.'
Hikigaya accepted his defeat. But at the same time, he had caught on to a very important clue.
In what situation would one only be able to roughly estimate the number of coins, but not know the exact amount?
That would be — weight.
'If she knew from the start the weight of the coins in my hand... then it all makes sense.'
'She slowed down her coin dropping on purpose to give herself time to calculate.'
'Then narrowed it to a general range, and used the sound to eliminate outliers.'
'If my reasoning is correct...'
Hikigaya once again focused on Rurichou's watch and the large piggy bank on the table.
There can only be one truth.