"...Hey, hey, are you okay, big brother?"

The little girl looked at me who is lying on the ground with her blue eyes. She straddled on me, that's why I felt the weight of her body. She's unnaturally light.

"...Are you okay? Are you still alive? He~llooooo...big brother? Are you there?"

She put her face closer to mine as she looked at me eye to eye, face to face. Her blue eyes faintly reflected the blue light from the magic stones embedded on the wall. Those eyes...bluer than the skies and the seas, as if that's the most bluish thing that one would ever see in his or her life. Her eyes shone like a jewel, and my eyes can't resist looking at them for some reason. But still, my mind can't process yet the sudden appearance of a young girl coming from nowhere, and the way she looked at me with those eyes.

"W-W-Wh-Whaaaaaaaaaaaa--!!!"

My body jolted as I get up due to the sudden turn of events. While looking at my surroundings in confusion, I saw the little girl at my side still looking at me with a perplexed expression but mixed with curiosity.

The little girl has blue hair, and just as I said earlier, blue eyes, but I'm not sure since the light in this room is blue. Her waist-length hair is styled into two pigtails tied with white fluffy ribbons, and she wears a white one-piece dress. She also has a cute face that looked like a doll and her way of smiling at me makes one feel a sense of warmth and happiness. She is way too perfect for a little girl having the age of an elementary school student. Maybe eight or nine years old, I guess?

"Thank goodness, you finally woke up, big brother! I was worried that something happened to you..." She said to me while letting out a deep breath of relief.

Cute...too cu...

W-W-W-Waiiiiiiiiiiiiiiiiiiiiit!!! Wait a minute! W-What did I just heard right now? Did she just called me "big brother"?! Hey, Hey, Hey!!!!!

"H-Hold it right there! W-W-Who are you, and why are you calling me 'big brother'?!" I crawled backwards as to distance myself from the girl.

"...Me? I'm your little sister!"

She said without any hesitation.

Hey, what are you saying, little girl?!

"No, no, no, no, no! That's impossible! In the first place, I don't even know you!" I quickly refuted what she said.

This little girl, what is she thinking?

"...But I am your little sister, and it's been decided!" She declared proudly while puffing out her flat chest.

"D-Decided? By whom?!" I asked her.

"...By me, of course!"

"HAAAAAAAH??!"

Did this girl just decided to be my little sister on her own accord? She kept on insisting on having me as her big brother and yet, my consent was not asked! Isn't that something wrong even if you look at it from all angles?!

"B-But that's impossible! I was stuck in here then I fainted due to some strange trap and suddenly, I got a little sister? H-How did that happened?!" I told her.

I kept on arguing with her but after about an hour I gave up and just sat quietly on a dark corner.

"...Hey big brother, you suddenly became quiet..." She said as she also sat beside me.

She noticed I haven't said a word for a while after arguing with her. Her face showed concern, but due to the current situation I'm thinking of it as a form of provocation.

"S-Something just crossed my mind for a bit...still, don't call me 'big brother'!" I said as I pushed myself away from her.

When will she give up on calling me that? I don't have any siblings to begin with.

I want to scowl at her, but she's only a little girl, and I think it's childish for me to lose my temper to a child.

"...B-But..."

"No buts! I don't even know who you are, and where you came from! Please, get away from me..." I said to her in a strong tone.

"...N-Never! I don't want to leave your side!" She insisted.

She wanted to get closer to me but I stopped her right away.

"Is there a reason why you're calling me 'big brother'?" I asked her.

The little girl got confused for a bit because of my question and upon fully understanding it, her emotion went down.

"...U-Um, because..."

"Because...?"

"...I can't get out of this room until now..." She answered in a faint voice.

Eh? Is she really trapped in here?! But when I entered here, there were no signs of her, so how is that even possible? I didn't know this girl has this much mystery in her.

"...Moreover, if I leave this place I don't know where I will go." She continued. For the first time, she didn't looked at me in the eye.

I don't know yet her circumstances, but it seems like she is stuck in this place for days. Maybe she's from somewhere here in the desert and just like me, discovered this cave and got trapped inside. There might be also a possibility that she's from somewhere else and just like the first case, went inside and got trapped. It's a mystery as to how she managed to reach this part of the cave, considering that one has to pass through those deadly traps and I noticed just now, she doesn't have any injuries in her. Could it be, she's a prodigy when it comes to exploring caves? Like some apprentice of some renowned adventurer?

Whoever that adventurer is, he must be still looking for her.

Damn, I suddenly felt guilty because of the way I treated her just now. I have to think of a way to help her. Think, think...

"...Um, if you like, you can go with me..." I said to her.

She looked at me again, this time in surprise. Well, I'm also surprised at my words.

"R-Really??" Her eyes regained their shine at that moment.

"Y-Yeah. Since I'm also trapped in here I thought that we could help each other get out of this cave. Moreover, it will leave a bad taste in the mouth if manage to get out while leaving you here alone. I also thought that it's not bad to have another travel companion...B-But, this doesn't mean that I agreed on being your big brother, you know? This and that are separate things! I hope you remember that."

She smiled again when she heard that.

"...Thank you very much, big brother!" She said happily.

"Like I said, don't call me 'big brother'!" I spoke to her with a glare.

"Hehehehehe..." She only laughed lightly at my words. Is she by chance, mocking me?

"A-Anyway, let's get out of here since I regained my energy--"

As I walked towards the door, I felt that the whole place is shaking. Then, I hear faint growls from somewhere.

"...B-Big brother! Look above!" The little girl shouted at me while pointing her finger towards the ceiling.

When I looked above, I saw two rock figures that looked like golems detaching themselves from the ceiling. They both have a size bigger than Prick, and have a blue-colored magic stone embedded on their chests.

I don't know why, but the golems released their killing intent towards me.

"Hey you, stay behind me!" I said to the little girl as she hides from my back.

I grasped tightly the mysterious black sword while pointing the blade towards them as I prepare myself to fight.