Third floor, Astronomy Club activity room.
The orange glow of sunset filtered through the curtains, casting scattered flecks of light into the room.
A girl in a black Gothic dress who looked nothing like a teacher appeared in the doorway.
Natsuki Minamiya raised her hand, and with a click, the fluorescent lights came on, bathing the entire classroom in brilliant white light.
After turning on the lights, Natsuki Minamiya looked into the classroom and immediately spotted the figures at three desks spaced a meter apart.
Her gaze settled on the faces of Luo Shu, Utaha Kasumigaoka, and Eriri.
"I thought this would be a private remedial lesson, but now I have three times the teaching to do?"
"I brought this on myself, but this is still one thoroughly unpleasant 'tutoring session.'"
Muttering to herself, Natsuki Minamiya walked up to the lectern, picked up the bag she had brought, and took out three clear glass bottles she had prepared beforehand.
The brown liquid inside the bottles swayed gently with Natsuki Minamiya's movements.
"Before we begin, I'd like to find out how much you know about this world's 'common sense.'"
At that, Eriri and Utaha Kasumigaoka blinked, then both turned to Luo Shu, who sat in the middle.
Under their gazes, Luo Shu said with an awkward expression:
"Natsuki-chan, you'd better treat all of us as complete beginners."
"Don't add pet names like 'chan' to my name."
Natsuki Minamiya snapped back reflexively, then frowned at Luo Shu and said:
"Now I'm starting to believe your claim that you know me."
The only people who added "chan" to her name as a term of affection were those "disobedient" students from her original world.
Hearing Luo Shu use that familiar form of address now left Natsuki Minamiya feeling inexplicably nostalgic.
"All right. In that case, I'll teach you as absolute newcomers."
As she spoke, Natsuki Minamiya placed the three bottles of unidentified liquid on their desks and said:
"Since you're starting from scratch, our first lesson will be how to identify danger."
Then Natsuki Minamiya turned toward the three of them, her small face stern.
"From this point on, I'll explain danger detection using the theories of this world's Eastern Occultists."
"Now rub the essential oil in front of you onto your eyelids, then close your eyes."
Without hesitation, Luo Shu opened the glass bottle in front of him, poured a little onto his fingertip, rubbed it over his eyelids, and closed his eyes.
Once he applied the essential oil, a distinct coolness spread over his skin, rather like applying medicated oil.
Utaha Kasumigaoka and Eriri followed his example, closing their eyes after applying it.
"Now focus your attention on your eyes. Without opening them, strain as though you're trying to make out a distant blackboard."
At Natsuki Minamiya's words, Luo Shu's brow tightened, and his eyeballs seemed to press against his eyelids.
"Good. Now slowly open your eyes. Remember, slowly, a little at a time."
Luo Shu slowly opened his eyes as instructed, and something about Natsuki Minamiya, standing at the lectern, looked different.
From Luo Shu's perspective, quietly burning flames had appeared over Natsuki Minamiya's left shoulder, right shoulder, and head.
The flame on her left shoulder was red, the one over her head was blue, and the one on her right shoulder was yellow.
"What do you see?" Natsuki Minamiya now held a pointer, which she used to indicate the space above her head.
"A blue flame," Luo Shu answered softly.
"Three flames. You're pointing to the blue one in the middle, above your head," Utaha Kasumigaoka added.
"Uh... same here." Eriri seemed unsure what else to add, so she could only say quietly that she saw the same thing.
"Very good. It seems the first step, Spirit Vision, was quite successful."
"Remember this sensation and this perspective. This is an essential skill for an occultist."
As she spoke, Natsuki Minamiya pointed to the flames over her shoulders and head.
"There's a saying in the East that the human body has three treasures: essence, vital energy, and spirit."
"Essence refers to the substances that form the foundation of the human body and sustain its physical existence. It specifically corresponds to the flesh.
Vital energy refers to a latent force that flows through the body and harmonizes its various parts. Of course, you can also think of it as life force.
Spirit refers to things such as thought, the mind, perception, and even the soul."
"From the perspective of spiritual perception, or Spirit Vision, essence is the red flame on the left shoulder, vital energy is the yellow flame on the right shoulder, and spirit is the blue flame above the head."
"Of course, they aren't actually fire. They're the spiritual light emitted by these three components of your body when viewed through a spiritual perspective."
"When all three flames are present and burning steadily, that indicates the person's health to a certain extent."
At this point, Natsuki Minamiya stood on tiptoe and wrote on the blackboard with chalk, adding a vivid drawing of a human figure.
"A dim red flame means the body has suffered damage. A dim blue flame means the mind has been harmed. A dim yellow flame means your body is gradually weakening."
"Most of the dangers we encounter, and the kinds of harm we suffer, can be identified by examining these three flames."
Natsuki Minamiya pointed to the steadily burning yellow flame on her right shoulder and
emphasized the warning:
"If the yellow flame dims, flickers, and gradually goes out, a spirit or ghost is most likely feeding on your life force."
"If the blue flame flickers, it means your mind is being influenced by an object or another living being. That influence is most likely an illusion, so if you notice this after activating Spirit Vision, be careful. Everything you see without Spirit Vision could be an illusion."
At this point, Natsuki Minamiya pointed to the blue flame above her head again.
"As for a dim blue flame, that means your mind is under attack. This is the most troublesome case. Enemies who do this usually intend to kill.
If the blue flame keeps shrinking, it means something is draining your mental energy. At that point, you should consider whether something has attached itself to your mind as a parasite, or whether you've entered some troublesome environment."
"Have you seen horror movies? Ju-on or Sadako, for example. If they existed, their attacks would generally work through the blue flame, inflicting damage on the mind."
Eriri shuddered reflexively at those words and looked up at the blue flame above her own head. It was fist-sized and burning steadily. Good, she was fine.
Meanwhile, Natsuki Minamiya continued her lesson.
"As for the red flame flickering, dimming, or even weakening, that's more obvious: your body has been injured. Knife wounds, gunshot wounds, even certain hidden illnesses-the condition of all these injuries will be reflected in the red flame."
Natsuki Minamiya picked up the teacup on the lectern, which held the coffee she had brewed.
She took a small sip, then looked at the three students below her, who were absorbing the information.
"Is there anything you don't understand?"
Luo Shu considered for a moment, then raised his hand and asked:
"Can two flames, or even all three, start flickering or shrinking at once?"
Natsuki Minamiya paused at the question, her insulated cup stopping in midair.
Then a pitying smile appeared on her face.
"In that case, I'd have to congratulate you."
"Congratulations. You've come into contact with the Abyss."
Before you continue