The mist thickened.
Moonlight poured over the mountain forest ahead, and the oncoming wind carried a chill that cut to the bone.
The pink-haired girl sped forward through the night, single-minded, rushing toward that lone mountain standing black in the shadows. The moonlight fell on that still-youthful face but drew out no emotion at all—only, compared to the girl who'd once appeared at the Butterfly Mansion, she was a little taller now, that tiny bit, her stern features now looking even sharper.
"This is Mount Natagumo."
An equally cool voice sounded behind her.
It belonged to a long-haired, lean-faced man. He looked steady and mature, but was in fact only just past twenty this year. Over his shoulders he wore a haori patterned differently on its two halves—one side plain deep red, the other a yellow-and-green checker.
His name was Tomioka Giyu, the Demon Slayer Corps' current Water Hashira.
"The stench of demons is thick here."
Tomioka Giyu stopped. By his first estimate there were at least four full-fledged demons, and among them one whose aura burned abnormally strong, as if in a berserk state.
Even an Upper Rank demon couldn't give off an aura this dense—that would be handing your location to every demon slayer nearby.
"Let me check the time."
The pink-haired girl's expression stayed placid. She slipped a hand into her uniform and drew out something fuzzy.
It was a scrawny cat, white all over save for the very tips of its two ears, dabbed with a touch of pink. The girl gazed quietly into those cat's eyes glowing with a faint blue light and studied the pupils carefully... slitted thin as a ginkgo seed.
"Around four o'clock."
She lifted her head and answered her companion.
"...You actually tell the time from a cat's eyes? Doesn't that leave room for error?"
Tomioka Giyu frowned, thoroughly displeased. The ancients did judge time this way, true, but a cat was a living creature after all, and its range of accuracy was nowhere near a tool like a pocket watch.
"I don't keep it for nothing. It's got to earn its keep somehow."
The girl gave a careless hum, then patted the cat lightly on the rump. It was clever enough—quickly grasped its master's meaning and dutifully burrowed back into the pocket inside her robe.
"On a mission, any small slip can breed disaster." Tomioka Giyu had no intention of letting her off. "I suggest you buy a pocket watch next time, Flower Hashira."
"Not happening."
She suddenly flashed a sly little smile, as if deliberately needling him.
"...Hmph. Suit yourself."
Tomioka Giyu's brows knit tight, but all he could do was heave a long sigh and let the matter drop.
"Sulking?" she asked.
"No."
Tomioka denied it flatly.
"Tomioka, how are you still exactly the same? No wonder all the other Hashira can't stand you."
She mocked him in the tone of an old friend.
"...!?"
The man in the two-toned haori had just been about to put all this behind him and press on, but at those words he visibly stalled.
Just an ordinary line of banter... yet it landed on this aloof, arrogant-looking man like a critical hit.
"Tomioka-san, you couldn't have forgotten my name, could you? Or do you have some objection to being sent on this mission with me?"
"Ouma Mana."
He didn't turn around, but he spoke the pink-haired girl's name clearly.
"That's enough, isn't it? Save whatever you want to say for after the mission. Those Corps members still need our help."
"Okay~"
Mana agreed with a slight smile, deliberately drawing out the syllable.
The woman didn't have the faintest air of tension about her, as if she didn't take this mission seriously at all—she'd even brought a pet along on so important a job... If he weren't somewhat acquainted with her, he'd surely report her to Oyakata-sama when he got back.
Her name was Ouma Mana. Tomioka Giyu had first met her about two years ago, back when she hadn't yet become the Flower Hashira—just a newcomer freshly through the Final Selection.
Tomioka Giyu had taken an emergency mission and set out for a house deep in the remote mountain forest, but in the end he'd been a few steps too slow. The whole family, young and old, was already dead, save the eldest son, who'd been spared because he was out delivering charcoal and hadn't returned—though his little sister had been turned into a demon. After that, because he was so poor with words, Giyu had nearly been accused of the murders. Fortunately Insect Hashira Kocho Shinobu had rushed over with Ouma Mana, and after twists and turns his name was cleared.
Still, they were no more than acquaintances. Tomioka Giyu really was on bad terms with all the other Hashira—let alone a woman who'd seen him make a fool of himself, and who later became the Flower Hashira, his equal in rank.
And in that very moment, a sudden thunderclap exploded in their ears. But now the bright moon hung high; forget rain, the night sky was pure and clear without so much as a wisp of thundercloud. Where had the thunder come from?
"Was that thunder?"
Mana pinched her lower lip, puzzled.
"That's Thunder Breathing."
Tomioka Giyu gazed at the last sliver of golden light lingering under the moon and sighed softly.
"I didn't expect there'd be a Thunder Breathing swordsman this remarkable among them."
"Ah!"
The girl suddenly gaped, her eyes lighting up.
—Could it be that child?
"Did something occur to you, Flower Hashira?"
Tomioka Giyu looked at her.
He seemed determined not to address Mana directly by name.
"Nothing. Maybe someone I know."
Mana shook her head, sweeping the placidity from her face for a few added measures of seriousness. She closed her eyes and, with practiced ease, felt out the rough auras of every demon on the mountain, and identified two likely locations among them.
No more words were needed. Mana and Tomioka Giyu traded a glance, then split up and made for the regions where the demons' auras were thickest.
...
...
Meanwhile, in a small grove somewhere deep in Mount Natagumo.
The night wind was cold, but there was no howl to it. Everywhere drifted the reek of blood and the smell of soil... and those threads hidden in the air, so fine they were almost imperceptible.
A red-haired boy in a black-and-green checkered haori, gripping a snapped half of a Nichirin Sword, hauled his battered body forward in a headlong charge... Consumed by fury, his face streaked with blood, he swung his blade forward like a wounded beast driven mad.
His name was Kamado Tanjiro—the very child from the earlier story who'd been spared because he'd gone out to sell charcoal.
Now he was a newcomer to the Demon Slayer Corps, a Mizunoto—the lowest rank of Corps member.
Before him stood a white-haired boy who looked frail to the point of collapse. His waxen skin already marked him as a demon, but more terrible still, characters were carved into his eyes, forming a single simple word.
—Lower Rank Five.
In his opponent's eyes, the boy's movements were laughable, absurd—all bluster and thunder, riddled in truth with openings.
"I'd have thought you weren't naive enough for this. You don't actually believe that just getting close to me gives you a shot at winning, do you?"
The Lower Rank Five demon twitched three fingers, drawing up several silver-glinting threads to strangle the boy.
"Water Breathing, Tenth Form: Constant Flux!"
With that broken blade alone, Tanjiro somehow brought forth a vivid dragon of surging water.
The blade swept through one graceful, flowing arc after another, and with a dragon's roar it severed every strand of spider silk the Lower Rank Five had spun!
"You think my threads are only that strong? Hmph... Blood Demon Art: Cutting Thread Cage!"
In the blink of an eye, the threads barring Tanjiro's path were dyed blood-scarlet—the demon had gotten serious! He'd unleashed his Blood Demon Art!
The transparent threads shimmered with a ghastly bloody light. Tanjiro clenched his teeth, and despair gradually closed in on him. He did not even need to test them to know the truth.
—I can't cut these red threads.
Because he was simply too weak now... nowhere near a match for the Twelve Kizuki. But he couldn't retreat, because the one behind him was the only family he had left in this world! His most precious little sister!
—I'm sorry... Nezuko. Looks like this is as far as I go.
Tanjiro shut his eyes in despair, quietly awaiting the moment these threads carved him into pieces. No matter how fiercely he refused to accept this ending, no matter how firm his resolve, none of it could bridge so vast a gap in strength.
And in that instant, he suddenly heard that voice from within his heart—the voice that appeared whenever he found himself trapped in desperate circumstances.
After a brief daze, Tanjiro's eyes abruptly changed. Even his entire presence changed. His frustration, anxiety, rage, and grief vanished without a trace.
Here now stood a cold, merciless demon slayer.
"...Sun Breathing, Third Form."
He spoke the technique's name, unhurried.
"Raging Sun."