Special thanks to Chiliblossoms, who helped me with ideas for this story.

Maybe this wasn't the best idea after all, I thought as we climbed the steep path up the mountain. Sure, I'd been to this mountain quite a few times before. Sure, I was always paying attention when we came here. Sure, I downloaded a map of the whole place from my father's phone and sent it to mine when he was distracted. And sure, we had a really good reason to be here.

But really, my sister and I didn't actually know what we were doing here.

I looked behind me. I could see the entire skyline of Kunugigaoka spread out. It was a legendary city, thanks to that little incident twenty-three years ago. And if the pictures were to be believed, a lot has changed. We live thirty minutes from three different malls! The town's population exploded at around the time I was born, though most everyone commutes to Tokyo during the day. And every August, we have the biggest Obon festival in the prefecture-

"Aguri!" My little sister poked me in the ribs. "Why'd you space out? There must be something really interesting over there."

"Huh?" I turned around to meet Hotaru's amber eyes. "Not much. Just lost in thought, I guess." The truth was I had just read a big book on the history of Kunugigaoka and was itching to share what I learned with someone. Maybe my sisters and my parents would listen to me talk about it after dinner tonight. They always did ask me "What did you learn today?"

Twenty minutes later, I was still convinced we were on the right path. Even though some unfamiliar things were popping up. But I had to be sure.

"Do we have an emergency escape plan?" I swatted a gnat that had been buzzing around us for the past half hour.

"We don't need one. This mountain is private property. So unless someone from the extended family decided to come here right now, we won't be discovered." Hotaru smiled sweetly. She was correct, the only 'person' (or what could pass for one) who might have been tracking our location was Ritsu. She's never shown up on my phone before, but maybe copying the map from my father's phone transferred her to my device… And maybe she also read my embarrassing text messages to my crush... Ahh, I couldn't stop thinking about such things!

"I mean, are we technically trespassing if Mom and Dad said we could be here?" I tried to convince myself, quickly checking the map.

"No we aren't, stop being paranoid." Hotaru skipped up the rocks, humming the song from My Neighbor Totoro.

"I am not paranoid! And be careful!"

It all started last night. We were both woken up at 11:36 pm on the dot. I found my sister in the kitchen, drinking a glass of water. I poured myself one too, and we sat staring at the wall for what seemed to be hours. I finally spoke up.

"You know how Mom and Dad were talking about Koro-sensei today?"

"So you were thinking of him too." She sighed, putting her dishes in the sink. In the other room, we could hear our youngest sister Fujiko throwing up, and our parents rushing out of their bedroom to tend to her. It was like this every night for the past month.

"Yeah. You know how they said that they leave out offerings for him? Candies and porno mags and such?"

"Yes." She opened up a package of pudding, and sat down with a spoon. "I wish I didn't know about the porno mags, but we have Uncle Okajima to thank for that."

"Err, yeah. Anyway, I want to do that too." My sister expected to hear that from me, and I know it. And I expected what I heard from her next.

"… So do I."

A very pregnant pause. Then more retching noises and sobbing.

I gulped. "Do you think he'd listen to our requests? Do you think he can-"

"Yes."

So here my sister and I were, on the Koro-sensei Memorial Mountain 12 hours later. Completely on a whim. Well, it wasn't completely on a whim, we had our reasons to be here. In my backpack, I was carrying a big bag of strawberry cheesecake Kit Kats and a note my sister and I wrote to this octopus we never got to meet. I can still remember what it said, which sentences were my idea and which were Hotaru's. Fujiko even added a few words, then crawled back into bed to take another six hour nap.

"Hey sis? What's the time?"

My sister unlocked her phone. 10:23 in the morning. Wednesday, August 17st, 2039.

I was hoping we could make it home by the time Mom and Dad got home with our younger sister. They took her to the Takebayashi General Hospital, all the way in central Tokyo. They trusted a doctor there most of all, one of our many uncles. If we couldn't make it home by then, we would at least stop by the store and buy a bag of Fujiko's favorite candy. We were told to clean the house, but… Priorities.

Before we ventured further, I sent a loving text to Fuji-san.

I'll pray to Koro-sensei for your health.

She immediately responded with a thumbs up.

"How much further to the top?" Hotaru asked me once we were in a thick bush, I could see out of the corner of my eye that she was scratching the bug bites she probably got due to the 37 degree Celsius weather.

I consulted the map on my phone. "Half a kilometer."

We climbed up a tree to get to the next ledge. We knew there was an easy path right near us, but we could find it even with the map. My sister was slouched over on me, catching her breath.

"I think we should have waited for the weekend and asked Mom and Dad to take us." Hotaru confided in me.

"Who knows what could happen in the next three days?" If it were anyone but Hotaru saying that, I think I would have snapped. "I think this counts as an emergency. And besides, we've navigated around Tokyo on our own before. We'll be fine."

My sister reluctantly nodded, and we marched forward.

And not even five minutes after I said that, we came to a giant pine tree that overshadowed a creepy cave.

Now we were in unfamiliar territory. Neither of us had even seen this before.

I walked towards the cave. Casually, as if I were walking to school. A raven flew over my head. Huh. I didn't even know we had those on the mountain. Hotaru followed closely behind, nervously grabbing my arm.

She began to hyperventilate. "Aguri? I'm having some serious doubts about this."

I paused, tapping the dirt off the soles of my shoes. My sister was the bubbly one between the hours of 8 in the morning to 10 at night (not a minute after 10 though; that was sleepy time). There was only thirteen months between us, but one could think it was thirteen years with the way she was acts within ten feet of a dessert shop. For her to be the voice of reason, I must be going something monumentally stupid.

"I'm just taking a look." I explained. After all, this whole adventure was my idea... But I immediately realized I really didn't want to inspect this creepy tunnel, not even in broad daylight. But something told me too. Maybe it was the ghost of Koro-sensei?

"Y'know you really shouldn't have worn white. That dress was meant for the next reunion." Hotaru slapped a mosquito.

"I guess I'm not exactly known for planning ahead." I shrugged, and shined my phone's flashlight down the cave. "That was Koro-sensei's specialty, they say."

Upon closer inspection, it was clear that this was less of a tunnel and more of a hole in the ground. It dipped down at about a 45 degree angle, and was full of jagged stalagmites. Most curious of all, a weird smile was engraved on the side of the cave. It had exactly eight big teeth, beady little eyes, and no nose. I immediately knew who it was. I put my phone away, as my palms were now too sweaty to handle it.

Under normal circumstances, seeing photos or drawings of this octopus, the one who my parents and aunts and uncles owe so much to, the same one I was going to humbly ask for assistance from, would comfort me. When I was an infant my mother knitted me a plush of him. He was still sitting on my dresser, I had ruffled his head for luck before I left. But it was not normal circumstances right now. This had bad news written all over it.

"I'm not going in there." I breathed as reality hit me like a freight train. I was a connoisseur of horror movies, my mother and I would watch them, especially the ones she'd starred in as a child. I knew the tropes. Teenage girl dressed in white: I'd probably see all my friends killed by whatever the hell it is that lives in my mirror, then be forced to make a pact with some celestial being to confront it and emerge from the cave at 4 am dripping with blood. Nope. Pioneers never say die, but they do have a very high mortality rate.

"Yeah, I'm not either. This is a terrible idea. Let's just go home and talk to-" Hotaru began to walk away, but she suddenly tumbled back, into the cave. She didn't even let out a scream, her eyes just revealed an expression of pure panic and terror.

"Hotaru!" I chased her in, and found my arm grabbed by some… It felt like a hand? But I could just feel the negative energy coming from it. Whatever it was, it wanted my sister and I in this cave that lead to God-knows-where. I knew it wasn't Koro-sensei.

I flailed around. Once I finally made contact with something fleshy, I knew it was Hotaru's leg and pulled on it, yanking my sister closer to me and clutching onto her for dear life.

It was then that she began to scream. I began to scream too, though I wasn't sure if anyone else could hear it. Then, we were overcome by blackness.

Thud.

I was woken by my sister poking me in the face. "Aguri, you better take a look at this."

"Wha…" My bones felt stiff, and like they were made of iron.

The sunlight guided us out of the cave. I stretched, grabbing a nearby stalagmite for balance. My bones cracked; I was too young for that!

What I gazed upon blew my mind. Kids our age, in those gray uniforms we had seen before, walking up the mountain. I could only see them from a distance but they looked very unhappy. This mountain hadn't been used by the school for twenty-three years. There should be no students here.

Quickly, I unlocked my phone.

Friday, April 3rd 2015.

"So..." Hotaru shuddered as she showed me that her phone had the same display.

"So... What do we do now?"

Author's Notes:

1. If you follow me as an author, I'm currently writing a sequel to Great Teacher Nagisa. I expect to publish the first chapter in late March or early April.

2. This was partially inspired by Fallen Demonic Angel's Experiencing the Past, but it's going to have a slight twist. *Wink*

3. Many of the OC's I will feature here will be the children of E Class. Prepare thy heart.

4. Aguri and Hotaru praying and making offerings to Koro-sensei and believing that he can heal their sister may not seem to make sense if you're a Westerner reading this, but in Shintoism (the folk religion of Japan) it's customary to pray to ancestors and dead loved ones for their intercession.

5. Please tell me what you think in the reviews. I'm not sure I like how it came out (plus I've not been feeling myself as of the past few days), so if it's not good I'll rewrite it.