Early that morning, the Kasugai Crow delivered an order, instructing Shinobu Kocho to head to the Shinetsu region in the west as soon as possible and rendezvous with the Water Hashira, Giyu Tomioka.
According to reliable intelligence, the area around Mount Myoko in Shinetsu was likely the headquarters of the Eternal Paradise Faith, a group the Demon Slayer Corps had previously been keeping a close watch on.
Recently, several young women had gone missing, and all clues ultimately pointed to that region.
Considering the events of the Mugen Train, although the culprit had been a Lower Rank of the Twelve Kizuki, an Upper Rank had been lurking behind the scenes.
The leads in this case had surfaced suddenly. No one knew what kind of danger might be waiting there, so the Master ordered the two of them to investigate together.
If the situation proved unfavorable, they were to retreat immediately. There was no need to engage in battle.
During this time, Shinobu had been temporarily staying at the Rengoku residence, observing Kyojuro's recovery while also handling tasks such as offering guidance at nearby convalescent houses.
With the order issued, she had to depart.
Asuka, who had already gained a basic understanding of how Flame Breathing functioned and had been planning to return to Hayama to visit his master, changed his mind after learning that Shinobu would be undertaking a mission where an Upper Rank might appear.
"I'll go with you."
"…Asuka, you've only just recovered from your injuries. There's no need to push yourself."
"I don't think I'm pushing myself." His expression turned serious. "Upper Rank demons are strong. You're not their opponent."
"…Mr. Asuka, could you perhaps not put it so bluntly?"
Though Shinobu was smiling, the corner of her eye twitched slightly, and the warmth in her smile diminished.
When she was with Asuka, she didn't need to maintain a gentle facade all the time. Otherwise, she might end up with internal injuries from being irritated by someone who, like Tomioka, simply didn't know how to speak tactfully.
After conveying this temporary decision to Master Ubuyashiki, the three of them set out west.
Why three? Because Shinobu's Tsuguko, Kanao Tsuyuri, had also been specially summoned to accompany her on the mission.
After Tanjiro and Kanao had that heart-to-heart conversation, the young girl had become much more talkative.
At the very least, she no longer remained completely silent whenever Asuka spoke.
Thus, the three bid farewell to the Rengoku family and boarded a train bound for the Shinetsu region.
Although Asuka had developed a certain aversion to this mode of transportation, it was undeniably convenient. They could reach their destination within a single day, so he silently followed Shinobu onto the train.
The daytime carriage was far more crowded than at night. Three people were squeezed into each row of seats. It was Asuka's first time witnessing such a scene.
Uncontrollably, he wondered if there had been this many passengers on the Mugen Train back then, would he have been able to save them all…
"Asuka, you haven't been having nightmares lately, have you? Your sleep has seemed quite steady these past few days."
Noticing his slight stiffness, Shinobu asked casually.
The three of them sat in the same row. Kanao was on the inside, with Shinobu in the middle.
Fortunately, both girls were rather petite, so even with three people sharing the seat, it wasn't overly cramped.
Asuka shifted slightly to give her more space, half-standing in the aisle himself. "…Since experiencing the Lower Rank's nightmare, it's been much better. At least it's not as unbearable."
He had thought a great deal about that dream recently.
Enmu's Blood Demon Art had likely, by accident, triggered something deep within his stream of consciousness—Aizen's projection.
Perhaps Aizen himself was the reason nightmares existed. Or perhaps, as that man had said, it was his own gradually unsealed spiritual pressure that lay at the root of those recurring nightmares.
In any case, since that battle within his mental world, the nonexistent fantasy realms and the past or future dreams of those around him had appeared far less frequently.
As for the future, whether Aizen's figure would appear again, he did not know.
"Come to think of it, I heard that Lower Rank's ability was supposed to create pleasant dreams… some sort of trick?"
With so many people around, Shinobu avoided using the term Blood Demon Art to prevent unnecessary attention.
Asuka nodded. "Unfortunately, I didn't have any pleasant dreams. I ran into someone I didn't want to see."
"Not Mr. Tomioka, I hope?"
"…Of course not. An enemy."
"You should continue taking the herbal medicine for a while longer. It'll help restore your spirit…"
"…Forgive my intrusion, you two…"
Just as Shinobu was advising Asuka, a man's voice suddenly sounded from across from them, carrying a hint of concern.
All three turned toward the source.
The speaker was a middle-aged man who looked to be in his early forties.
He sat between two burly farmers with thick stubble. His thin frame, draped in a dark brown suit, looked somewhat out of place.
Round glasses rested on the bridge of his nose, and he wore a neatly trimmed mustache. His gaze was gentle. "My apologies for interrupting your conversation."
He sat much more upright than the two large men beside him, hands folded somewhat nervously on his knees. Beneath them lay a thick, hardbound medical book. Even in the cramped environment, he was doing his best to maintain his composure.
"I happened to overhear you mention nightmares, and I noticed this young gentleman seemed somewhat unsettled…"
"As a doctor, perhaps it's a professional habit. When I see someone troubled by illness, I can't help but ask a few questions."
Asuka looked at him deeply, a trace of caution in his eyes toward the stranger who had suddenly spoken up.
"Oh? You're a doctor?" Shinobu reacted differently, her voice carrying respect.
Having grown up in a family of pharmacists, she naturally felt goodwill toward medical professionals.
The man nodded slightly and carefully took out a simple leather identification holder from his inner pocket.
In doing so, he accidentally nudged one of the large men beside him and hurriedly apologized before unfolding the ID for Shinobu to see.
"My apologies, I haven't introduced myself yet. My name is Fujino Genkuro. You could say I'm just a country doctor."
"Judging by your attire and bearing… are you a young couple traveling together?"
Asuka showed little reaction, but Shinobu froze for a moment. A faint blush spread across her gentle smile, and even Kanao cast a quiet, curious glance their way.
"No, no, you misunderstand. We… we are colleagues and friends, that's all…"
Realizing he might have misspoken, Dr. Fujino put away his ID somewhat sheepishly and turned to Asuka.
"Then I must have been presumptuous. In that case, young man, may I ask about your condition?"
"Mm." Asuka glanced at Shinobu, then nodded.
"Do your nightmares come with palpitations, night sweats, or extreme fatigue? Before sleep, do you feel gastrointestinal discomfort, fever, or…"
His questions were detailed, largely from the perspective of Western clinical medicine. Even Shinobu felt she had learned something new and quickly jotted notes in the small notebook she carried.
"…I believe I have a general idea now. Besides herbal medicine, I would recommend visiting a well-equipped modern hospital for a thorough examination."
"In the meantime, you could try drinking chamomile tea before bed. It also helps calm the mind."
He sincerely offered his advice and scribbled what looked like an illegible prescription on a slip of paper.
"When you reach a major city like Tokyo, you can show this to a pharmacist along with my diagnosis. It may be of help."
"Thank you so much." Shinobu accepted the note with a graceful smile. "I'll make sure he pays attention. By the way, are you also heading to Shinetsu?"
Dr. Fujino neatly put away his pen and paper. "Indeed. Taking advantage of some rare leisure time, I'm going to visit relatives in Nagano Prefecture."
"I've mostly made a living in Sendai and Tokyo. I haven't had much chance to visit the Shinetsu region. I hear the snow scenery there is beautiful. I thought I might stay for a while and experience the local customs."
His tone carried a quiet longing for nature's serenity, even as he remained wedged between the two burly men.
"What a coincidence. We're also planning to head to Mount Myoko."
"Mount Myoko? An excellent choice! They call it 'Little Fuji,' and there's even a legend about a snow woman. It's well worth visiting!"
The two chatted back and forth, and the once dull train ride passed quickly.
Leaning slightly forward as if sharing a secret, Shinobu deftly guided the conversation.
"Mr. Fujino, since you have relatives there, have you ever heard of a sect called the Eternal Paradise Faith? I hear it's quite popular."
"Eternal Paradise Faith?!"
The gentle smile vanished from Fujino Genkuro's face as if something had stabbed him.
His brows drew tightly together, and the corners of his mouth turned down. The warmth in his eyes was replaced by something far more complicated.
There was unmistakable disgust there—along with deep concern.