Kaigaku refused to believe Zenitsu's explanation.
"Impossible! You're lying! Thunderclap and Flash could never reach that kind of speed or power!"
"I have no reason to lie to you," Zenitsu said calmly. "My talent is limited—I could only master Thunderclap and Flash. So I had to refine it, improve it, to prepare for the battles to come."
Kaigaku's thoughts immediately turned to Yosuke.
"It must have been Yosuke Ubuyashiki! There's no way a worthless idiot like you could improve a Thunder Breathing form on your own!"
Tanjiro couldn't comprehend Kaigaku's stubbornness.
"Why are you like this? Why can't you acknowledge Zenitsu's effort?"
"I don't believe it! I don't believe it!!" Kaigaku roared, his voice bordering on madness.
Inosuke couldn't help but laugh in disbelief.
"I've never seen anyone like you! You lose and then keep making excuses for yourself—what a joke!"
Kaigaku glared at the three of them—Zenitsu, Tanjiro, and Inosuke—with pure resentment.
"This is all your fault! If it weren't for you, Yosuke Ubuyashiki would've trained me! I'd be stronger! It's all because of you!"
A calm voice sounded behind Zenitsu.
"It seems my first impression of you was entirely correct."
Yosuke appeared silently at Zenitsu's back.
"You're nothing but a selfish egotist."
Kaigaku's heart sank the moment he saw Yosuke. It meant Yosuke had been watching him all along.
Now, his trial was in ruins. He knew the Demon Slayer Corps would likely expel him after this.
He glared at Yosuke, fury and despair twisting his features.
"So you never planned to teach me at all, did you? You were just toying with me!"
Yosuke's tone was cold and detached.
"Toying with you? For amusement? Don't flatter yourself. You're not worth that.
If you had passed the trial, I would have honored my word and trained you. But you failed."
Kaigaku's hateful gaze swept over Zenitsu, Tanjiro, Inosuke, and Yosuke.
He said nothing. His body was broken—he no longer had the strength to fight back.
Inosuke scowled at the sight of Kaigaku lying on the ground.
"So what do we do with this guy now?"
Exhausted, Zenitsu took a deep breath and replied,
"Let the Demon Slayer Corps handle it. Anyone who does wrong must face the consequences."
Tanjiro's Kasugai crow flew off toward headquarters to report the situation.
Not long after, several members of the Corps arrived and took Kaigaku into custody to await judgment.
Over the next few days, Zenitsu was gloomy and despondent.
He didn't eat, barely drank tea, and looked utterly dejected.
Seeing their best friend like this, Tanjiro and Inosuke came up with a plan—a whole series of them—to try to cheer him up.
Zenitsu lay listlessly on the engawa, basking in the afternoon sunlight, his expression vacant.
Inosuke burst out energetically in front of him.
"Zen-guy! Let's fight!"
Zenitsu barely opened his eyes, his voice weak and lazy.
"Oh… it's you, Inosuke. A fight? Sorry… I'm going to sleep. Maybe next time."
Faced with such a limp, spiritless Zenitsu, Inosuke was defeated.
Then Tanjiro appeared, smiling warmly and carrying a tray.
"Zenitsu, look! For lunch today, I made your favorite—eel sushi! I even brought extra just for you!"
Zenitsu mechanically picked up a piece and ate it, but he left the eel untouched.
"It's delicious. Thanks, Tanjiro," he murmured faintly.
Tanjiro frowned.
"Zenitsu, why aren't you eating the eel? Isn't that your favorite part?"
"There's eel? …I forgot. Never mind, I'm full."
He lay back down, closing his eyes once more.
Tanjiro—defeated.
The two friends exchanged glances and withdrew to a corner to whisper their next move.
"Ino—uh, wait, San-taro, what are we gonna do to cheer him up now?"
"It's Tanjiro! But seriously, we've already tried everything. This must've hit Zenitsu really hard…"
Inosuke's eyes gleamed mischievously.
"San-taro, I've got one more idea!"
He leaned in and whispered his plan in great detail. By the time he was done, white steam was puffing excitedly from his boar snout.
"Are you serious?!" Tanjiro blushed furiously. "That's… that's way too embarrassing!"
"We're comrades! It's fine! Come on, let's go!"
Before Tanjiro could protest further, Inosuke grabbed his arm and dragged him off—straight toward the Butterfly Sisters' room.
Just as Inosuke was about to push open the door, Tanjiro balked.
"No, Inosuke, we can't! This is definitely a bad idea! If they find out, we'll never be able to show our faces again!"
"It's fine! They haven't been back in ages. As long as we keep quiet, no one'll know!"
With a loud kick, Inosuke burst through the door, dragging a panicking Tanjiro behind him.
Helpless, Tanjiro could only surrender, muttering to himself,
"This is all for Zenitsu… this is all for Zenitsu…"
Inosuke began rummaging through the room, tossing clothes everywhere.
"This one's too big! Can't wear it!"
"Huh? How do you even put this on?"
"Wait, is this a shirt or pants?"
He muttered and threw garments over his shoulder one after another until the room was covered in fabric.
Tanjiro groaned.
"Inosuke, stop making a mess! We'll have to fold all this back up later!"
"It's fine! I told you—they haven't been here in ages! We can do whatever we wa—"
Before he could finish his sentence, a dangerously sweet voice came from behind them.
"Oh my… do whatever you want, was it?"
Inosuke and Tanjiro froze. Slowly, they turned around—
and there stood Shinobu Kocho, Kanae Kocho, and Kanao Tsuyuri.
A vein bulged on Shinobu's forehead.
Kanae's expression was complicated, a teasing smile playing at her lips.
Kanao's face was blank, but the faint furrow of her brow radiated quiet disapproval.
Kanae's gaze fell to the garment in Inosuke's hand—an unmistakably private piece of clothing. She spoke in a lilting, amused tone.
"My, my… it seems Tanjiro and Inosuke are finally at that age, hmm~?"
Tanjiro's face turned crimson. He frantically tried to pry the garment out of Inosuke's hands.
But Inosuke held tight, pouting,
"What's your problem, San-taro?! I finally found one that actually fits me!"
Tanjiro was seconds from fainting, sweat dripping down his temples.
"Inosuke! Just look around you!"
As they tugged back and forth, the fabric tore with a sharp rip.
Tanjiro's eyes went blank.
It's over.
He darted his eyes around the room, desperately searching for a crack in the floor—
any hole small enough to crawl into and disappear.
I can't show my face ever again.