I was currently at the site of an abandoned factory in the neighboring prefecture."Next to me was Aookuji, carrying her sword designed to fight abyssal beasts—the "Ha-Kane."

    After I wrapped up my home visit, we rushed here, but it was already close to 8 p.m.

    “Haa… it’s here. The inside of this factory must be ‘abyssalized.’ Can you feel it too, Sensei?”

    “Yes, it’s swirling with magic. More importantly, are you okay?”

    “Ah, yes…I’m much calmer now.”

    Since it was urgent, I had carried Aookuji on my back, using continuous wind magic jumps to cover the 20 kilometers. But I think it was a bit too much for her; she didn’t seem to be the thrill-seeker type. When I set her down, she looked pale and limp, but after a five-minute rest, her color had returned to normal.

    “But ‘abyssalization’... I never thought a dungeon would appear in Japan.”

    “A dungeon…?”

    “Yes. In the other world, places like this were everywhere. I would conquer them as I came across them, but there was no end to it.”

    That might have changed now that the Demon King’s power is gone, but this isn’t the time to reminisce.

    The reason we were here was that a dungeon, referred to as the “Abyssal Cave,” had appeared yesterday. Aookuji had been tasked with investigating it, and I was asked to assist her. Originally, her “Master” was supposed to come along, but they were away investigating another Abyssal Cave, so she was left to tackle this one alone.

    I could have declined, but I couldn’t let Aookuji, one of the top adventurers in the world, face it alone. And calling myself a “hero,” refusing would be unbecoming.

    They mentioned payment, but I wasn’t familiar with the rates, and Meiran Academy probably wouldn’t allow side jobs, so I’d likely turn it down.

    “…Phew, okay, I’m fine now. We’ll enter the Abyssal Cave from here. Thank you, Sensei.”

    “Got it. I’ll handle the support.”

    With her calm composure restored, Aookuji and I entered the abandoned factory.

    A dungeon is a labyrinth where monsters roam. In the other world, there were two types: the "static" dungeons that have always existed in certain locations, and the "emerging" dungeons that appear suddenly. The Abyssal Cave was one of the latter. If left unchecked, these dungeons would overflow with abyssal beasts—similar to those in the other world.

    Once inside the factory, the interior was nothing like the original building. Though the walls and floors resembled a factory, the place had been transformed into a long, dimly lit corridor about three meters wide.

    It felt very much like a dungeon.

    “Let’s proceed. Be careful—multiple abyssal beasts could appear.”

    “Understood.”

    I drew my mithril sword from my space magic. Since I’d be supporting Aookuji, I prepared some magic as well.

    We hadn’t gone far when the passage split into two. Aookuji checked her smartphone, which had a mapping function. The dungeon strategies in this world were surprisingly advanced.

    As we continued, I wondered why she was still wearing her school blazer. Was it her combat uniform?

    While thinking about that, I sensed multiple magical presences gathering nearby. An encounter? Yes, they were closing in.

    “Here they come! Type D—five of them!”

    Aookuji readied her Hakane.

    The creatures that emerged were squat, caterpillar-like monsters with numerous tentacles sprouting from their heads. Quite creepy.

    Oh, wasn’t the Type D an imitation of a "roper"?

    “Aookuji, are there many types of Type D?”

    “Huh? Yes, there are. We’ve identified 12 species.”

    I see. So “A, B, C, and D” just signify different ranks. Good to know.

    The giant caterpillars started moving toward us. They were weak, but having five attacking at once was still troublesome.

    What would Aookuji do? I watched as she used high-speed movement to slash the lead caterpillar, retreat, and then finish it off after dodging its tentacles.

    Her usual hit-and-run tactic. If she kept her distance and picked them off one by one, she’d be fine.

    After Aookuji finished the second one, the remaining three charged at me. I slipped between them with high-speed movement, cutting them all in half as I passed.

    “I’m sorry, Sensei. I didn’t mean to trouble you.” sea??h thё N?vel(F)ire.nёt website on Google to access chapters of novels early and in the highest quality.

    Aookuji sheathed her sword, looking apologetic.

    “Don’t worry about it. Just focus on what you need to do.”

    “Yes. But that last attack… You cut them in half with a single slash as you passed by, didn’t you?”

    “Yep. You usually swing your sword after you stop moving, but if you do it simultaneously, it’s more powerful. You should practice it, though it requires a lot of arm strength.”

    “That’s helpful, thank you.”

    Her serious response was typical of Aookuji. I should probably teach her some sword techniques from the other world while we’re here.

    “Let’s move on.”

    After collecting the Drop of the Abyss, we continued deeper into the dungeon. We passed through several forks and dead ends, progressing for about 30 minutes.

    Two more encounters with Type Ds followed, but Aookuji handled them easily.

    Then came our fourth encounter.

    “Type C—three of them!”

    A six-legged abyssal beast appeared ahead of us.

    Perfect. I could use this to teach Aookuji how to handle beast-type monsters.

    “Aookuji, I’ll take care of this one. Watch carefully.”

    “Yes… I understand.”

    Realizing my intention, Aookuji moved back to observe.

    The Type C beast, about the size of a tiger, crouched into a fighting stance as I approached.

    The first one lunged at me.

    “Here we go!”

    I pulled it in close and, using high-speed movement, countered by slicing off its head and front legs in one swift motion.

    The next one attacked as soon as I landed, but I countered in the same manner, cutting it down with ease.

    After I finished off all three, Aookuji came closer.

    “I’ve never seen anyone defeat a Type C like that before.”

    “It’s not a common method, but it’s effective against fast-moving enemies.”

    “Yes. You lure them in, slash them down, and evade simultaneously. It’s the opposite of waiting for the enemy to approach.”

    I guess she understood. Time to move on.

    “Let’s continue.”

    “Yes, this way.”

    I felt more like a teacher here than in the classroom. But I guess that’s only natural when you’re dealing with something completely different.