"So, what's your idea?"

"Do you have some sort of spacetime magic or skill?"

"My spacetime magic is just normal and can't connect you to other worlds. What do you expect from me?"

"Hm, in that case, do you have something like an inventory or space where you can store belongings?"

"Oh like an [Item Box]?"

"Yeah, exactly like that."

"What about it?"

"It connects to a different space right? A space that holds your stuff."

"I mean that's true, it stores things in the boundary between worlds."

"Alright, that's fine. Can't we use that?"

"That's a no-go. Living organisms can't go inside the [Item Box] unless it's some kind of special skill but I don't know of anyone with that kind of storage capability."

"How do you get stuff out of it then?"

"Hm? Oh, you can reach your arm into it no problem though."

"If you can stick your arm in then can't you stick your whole body in?"

"It'll allow you to go in with half of your body and then it starts rejecting you with anything more."

"Can you create two portals for [Item Box] simultaneously?"

"No, only one can be opened by the skill. I think I could manage to open another with my magic since I know where the start and endpoints are though. I've never tried it and I doubt anyone has or will. Who needs to open the same [Item Box] from a different point at the same time by using a lot of mana anyway? Just one portal is fine for the intended purpose."

"If an [Item Box] rejects me with any more than half my body in it, and you open another portal to that same space which is pretty much like another [Item Box], it'll allow me to put my other half into it and nearly my whole body will be in the space of the [Item Box]."

"That sounds like a really stupid idea but we might as well try it. You can't fully go into that space though since you're upper and lower halves will be separated inside. That's assuming the second portal created by magic behaves the same as the one made by the skill."

"It connects to the same space so shouldn't the same rules apply?"

"I'm no expert on spacetime magic and am definitely not good with experimental stuff like this. Let's just try it. How else would you be able to use and control your unique skill anyway without inviting everyone? But, don't blame me if your body gets bisected, spacetime magic experimentation is risky."

"I got it, I got it."

[Item Box]

A portal about 2 feet in diameter appeared in front of me. The inside is pure black where nothing inside can be seen. It has a width and length but no height, truly a hole in space. I reached my hand out towards it.

"Wait!"

"What?"

"I need to disarm the traps first...your hand would've been blasted off otherwise."

"Scary...what kind of demon needs traps for their own [Item Box]?"

"It's not an inconvenience for me since I can slip past it effortlessly."

"...I don't know much of this world's common sense but I can tell that you're a bit weird."

After a couple of minutes, the traps were all disarmed and it was free to enter the mysterious space.

"Wait, is it going to overflow me with energy like when I entered this world?"

"No, then no one would be able to use [Item Box] since they'd just explode on the spot. The skill establishes a safe path through spacetime so it's fine."

"What about the one you create with magic?"

"That should be fine too since I'm just copying the magic layout of the skill. I have enough mana to execute it."

"I see...well, here I go..."

I first stuck my arm through the portal. It had no change in sensation. Apparently, Eris's [Item Box] is pretty high quality. It can store anything besides living organisms, has large storage space, and stops time inside. After confirming my arm, I shifted my body into it, first my other arm and then my head. I slowly pushed my torso in and...

"Ah, I can't get in any more than this."

A sensation similar to the time I was frozen upon being summoned is apparent here. However, it's only on my waist if I try to push further. My upper body inside feels a weird sense of floatiness. Inside I can see a mishmash of items from books to jewelry floating around in the darkness, illuminated by the small light from the portal. None of them are in my reach, but if Eris used the skill properly then the item would probably gravitate towards her hand. 

"Alright, Eris, make another one."

I probably look really dumb right now. I'm bent 90 degrees with my upper half in a volumeless portal. Another one opened behind me facing the other. I stuck my foot through, relying on touch. Then, I put in the other. The weird floaty sensation tickled my legs and defied gravity. I am now actually floating above the ground with only the area near my hip exposed. 

You have obtained the title, [The One That Can Float].

[The One That Can Float] - Title is given to one that can float. You gain extra control when floating.

"Alright, Eris, bring the portals closer together."

"U-uh yes!"

What's that hesitation for? Do I really look that dumb?

The portals came within a millimeter of each other. Suddenly...

"Aaah!"

"Huh? Eris you okay?"

I quickly pulled my foot out of the portal and placed it on the floor. I did the same for my other leg and pulled my head out as fast as I could. 

"Eris?"

I check my shadow but there's no response.

I look around me anxiously and then I saw it...a person. 

"Huh? Who're you?"

"Um..."

"That voice, Eris?"

A girl of small stature lay before me. In plain light blue silky clothes and a small black amulet wrapped around her neck. Her cute squishy features made my heart skip a beat. She has clear-cutting eyes and dark gold-shaded hair tied together with a few brownish clips. 

"Ehh!?"

"Um...hello?"

I'm speechless. While still in surprise she jumped back into my shadow. 

"Eris...is that your true form?"

"I can't hide it anymore...yes it is. Got a problem?"

"No problems, no problems! In fact, I'm blessed to have a cute companion."

"Oh look at you! Does this cheeky brat want to die?"

"Not at all! So, why show me now?"

"It wasn't my intention. When you're in between the two [Item Box] openings the majority of you left this world. Shadows are made when light is affected by a body and is projected onto a surface. In this case, your body was pretty much nonexistent and so the light just went straight through. The little shadow you created with the body left isn't enough for me to maintain my shadow form so I got kicked out!"

"Ah, and I came out when that happened huh."

"That's how it is. Now that you know I'm a cute girl don't go attacking me, you hormonal human!"

"I won't, I won't!"

"Hmph. I'll trust you for now."

"Anyways, your not a demon. I saw the demon generals earlier and they had things like horns, tails, and wings."

"Demons can have transformation abilities and can hide their features."

"So, you're saying that you can?"

"I don't know. Who knows?"

"You know!"

"Not telling!"

Eris looked like a human. Is this just her transformation ability? How many abilities does she have? She can reverse things, hide in the shadows, use high-level magic, sense beings, and potentially transform? There's no way I'd not be curious about who she is! 

"Well, whatever. I know what you look like so just get outside and let's do the experiment again."

"..."

"Eris?"

"It's embarrassing though!"

I facepalmed. She seems like she's the shy but mischievous type. Like someone who pulls a prank and hides behind someone else as they're being chased.

"Fine, then I won't look at you."

"...haha...I don't really care that much!"

"Wha--"

She appeared from my shadow and she smiled next to me. She's a bit shorter and looks to be my age. 

"Huh?"

"I'm just messing with you. Alright, [Item Box], [Spacetime Magic: Item Box]." (Spacetime Magic: Item Box is just another portal to the Item Box space made forcibly with mana without the skill that uses no mana)

I sighed grimly and performed the same action as earlier. A certain someone hidden in the shadows made me bail the first time but this time I'm going to control [Overpowering Aura] for real!

"Alright, I'm in."

The sensation between my upper and lower half feels the same, but in this [Item Box] space, they're separated by two portals. It must look really weird, well, I can't see it since it's so dark in here. I'm not here to see anyway, just to feel, feel my own unique skill. Let's begin. [Overpowerer] should help just a little...

[Overpowering Aura]

I felt the same as always. 

"Eris, you good?"

"Yeah, only a bit of it is escaping to Helvias so you only feel like a fierce high-level monster right now!"

"Only a fierce high-level monster you say...ONLY? I see...well this is better, at least it won't garner any super unwanted attention. Alright, now, how do I control a unique skill..."

Usually, you'd control some supernatural power by feeling its flow and using intuition right? Feel the flow of [Overpowering Aura]...

"Hm?"

Is this it? Like my body is wrapped in surges of power erupting continuously over and over. I can feel it, but now to change it...NOPE! No way can I do that! It's like a wave of pure strength is pushing my puny resistance through the floor! My head hurts to the point of a mild headache. Let's try again...yep it's unyielding like it's supposed to be. Can't you cut some slack even for your user?

"Are you alright?"

"Yeah, I'm done with training for now. I have a bit of a headache."

Eris canceled it all and I fell facefirst into the dirty floor.

"Oi..."

"So did you make any progress~?"

"I couldn't control it at all. It's like a single man trying to hold back a tidal wave."

"So are you going to give up?"

"Huh? Why would I do that? This is the only way for me to get stronger at the moment. Unless you have some useful magic to teach or are actually a martial arts expert?"

"Well, this affects my mana pool since forcefully opening a hole in space takes quite a lot. You might want to start treating me nicer."

She said it with a slight smirk.

"I can also teach you basic magic if you want. I'm not great at martial arts or swordsmanship though."

"That's fine. You've already done a lot for me."

"Like what?"

"I mean you told me about this world and you also allowed me to hide from the guys that came over."

"My ability was just convenient for the time."

"Now, you're the only one who can help me train my [Overpowering Aura]."

"That's just because of your weird idea."

She can be both super modest and pride incarnate...what a bizarre person.

"C'mon just accept my thanks."

"...fine...you're welcome, Haruko"

"That's right, Eris."

I didn't know it but Eris was really happy from just that little bit.