Sui was helping the old man back to the house.
Under the extreme force of Thunder Breathing, his prosthetic leg had twisted out of shape, unable to withstand the strain. He had only managed a single strike using the First Form before losing the ability to continue. Now, he had to rely on the girl to support him back inside.
"Next time, try not to get so obsessed with fighting, old man,"
the girl reminded him.
"You should've gone easy on me too, you brat!"
Kuwajima fumed, his beard practically bristling.
Instinctively, he raised his cane to knock her on the head—only to realize it had been shortened earlier, cleanly cut through by her blade. The smooth break meant it no longer even reached her head.
"Sorry. That wasn't intentional."
Sui noticed the shortened cane and comforted him without changing her expression.
"I'll find you a better one in town another day."
"No need."
Kuwajima saw right through her.
Though irritated, the exhilaration deep in his bones told another story—every part of him was alive with excitement. It was a satisfaction he hadn't felt in years—the joy of clashing blades as a swordsman.
Unlike his old friend Sakonji Urokodaki, who could patiently train disciples, Kuwajima found it difficult. It wasn't that he couldn't teach—it was that, as a former Thunder Hashira, the storm within his soul still raged.
His students were forged under thunder itself—body and will tempered like lightning.
Sui, however, was an exception.
Her presence was gentle, like the calm surface of a lake at noon.
At first, he had wondered if she might be better suited to Water Breathing under Urokodaki. But after crossing blades, he realized—
Rather than a lake, she was the sky itself.
And before the vastness of the heavens, what could express it better than thunder?
"Do you think I'm ready for the Final Selection?"
The old man paused.
"Where did you hear about that?"
The Final Selection of the Demon Slayer Corps—an ancient and brutal trial.
Held on Mount Fujikasane, surrounded by wisteria, it took place in spring or autumn. The test was simple:
Survive seven days on a mountain infested with demons.
Endure until sunrise on the eighth day.
Sui was the most talented student Kuwajima had ever taught—and the fastest to grow. In just two months, she had reached the level where she could draw her blade against him.
He didn't worry about her safety in the selection.
Even before learning Thunder Breathing, she had killed a demon that had devoured hundreds using nothing but an ancient blade.
Now, with proper training—
Even he could no longer fully grasp how strong she had become.
"Lord Shinjuro told me,"
Sui replied,
"To join the Corps, one must train under an instructor, learn Breathing techniques, and pass the Final Selection to receive a uniform and a personal Nichirin Blade."
"Then do you think your training is complete?"
the old man asked.
"You said so yourself."
Sui answered.
"I did?"
"Your blade told me."
She said calmly,
"My training is complete. It's time to graduate."
Kuwajima froze—then laughed.
"Fair enough. I really don't have anything left to teach you."
A trace of melancholy crossed his face. These two months had felt both long and fleeting.
"You're not going to miss me, are you?"
Sui reached out and patted his thunder-like wild white hair—only to have her hand swatted away.
"Don't flatter yourself, girl. This old man is quite popular."
Kuwajima crossed his arms.
"A letter came today via Kasugai Crow. Gyomei found a child from a temple—he wants to learn Breathing techniques and become a demon slayer. He asked me to take him in."
"Gyomei?"
Sui shook her head.
"Who?"
"Oh, right—you wouldn't know. Gyomei is a current Hashira of the Corps, a user of Stone Breathing. Extremely powerful. They say he still hasn't found a suitable successor."
"I see…"
Sui remained calm.
"When will this child arrive?"
"Since the Stone Hashira is bringing him personally, it shouldn't take long."
Kuwajima muttered, glancing at her. She, too, had been recommended by a Hashira. But judging from that night, Shinjuro had been tied up with urgent matters—otherwise, he wouldn't have left such a delicate girl to go nearly a full day without food.
"Do I need to prepare anything?"
"Just do your job as a senior."
The old man snorted.
"Before the Final Selection begins, teach your new junior well. Save me some trouble."
"I see."
Sui nodded.
Passing off teaching duties from one student to another so casually—capitalists would admire that efficiency, she thought idly.
Of course, she understood his intention: to build rapport.
But even now, he hadn't quite grasped her nature—
She disliked trouble.
And children were practically the embodiment of trouble.
"Wait here. I'll prepare some food."
The old man stood up. With a new prosthetic fitted, he moved somewhat awkwardly. Combined with his shortened cane, he limped toward the kitchen.
Sui, for all her strengths, was hopeless at cooking and housework. After one disastrous attempt, Kuwajima had never asked her to help again. Hopefully, the new child would be better in that regard.
As the aroma of food began to drift through the air—
A gentle knock sounded at the courtyard gate.
"Please wait a moment."
Sui said, stepping out to open it.
"Amitabha. This humble monk is Gyomei Himejima. May I ask who you are?"
Outside stood a towering man over two meters tall, prayer beads in hand, murmuring a Buddhist chant. A long scar ran across his forehead. Over his Demon Slayer uniform, he wore a brown kasaya inscribed with "Namu Amida Butsu."
"Sui."
The top of her head barely reached his abdomen. The sheer difference in size made her slightly uncomfortable.
Though, for her, it hardly mattered anymore.
With her eyes closed, she neither needed to look up nor down at anyone.
…But this man—
He didn't seem to be using his eyes either.
She sensed something unusual sweep over her—not sight, but another form of perception.
"So you are Miss Sui."
The man nodded.
"I have brought the child as promised. May I ask where Mr. Kuwajima is?"
"He's preparing a meal. Please, come inside."
Sui bowed slightly, adopting the manner of a proper host—something she had once learned at the shrine.
"Thank you. Come in, Kaigaku. There's no need to be nervous. This person will be your senior—and your family from now on."
Gyomei murmured another prayer and stepped inside.
With his towering frame no longer blocking the view, Sui finally saw the boy behind him.
Kaigaku…
Even with her eyes closed, she felt a faint discomfort from him.
As the boy followed Gyomei inside, unnoticed—
Sui slightly opened her eyes.
A strange pale blue shimmer flickered within her pupils, blooming like a flower.