(UT is Undertale. Also you are just extremely short for your age.)

~Y/N's P.O.V.~

I was running out of the ruins, scared that someone may find out what I truly am. I'm a kitsune with 5 tails. I have (Favorite Warm Color, or White) fur on my ears and tails. I may be 18, but I'm extremely short. People think that I'm around 6 when they first see me. What I was wearing to cover up my tails and ears, were my (F/C) beanie and my big (F/C) hoodie to hide my tails in. Back to what I was doing, I was running over towards this bridge/gate looking thing, when I stopped to take a breather. 

~Sans' P.O.V.~

I was walking towards Tori's door, when I saw a small blur run towards Pap's bridge. I decided to go see what it was, but what I say surprised me. A little girl around 6-7, was sitting down, breathing heavily. "Hey kiddo, you okay?" I asked, surprising the kid. "I'm NOT a KID!" She yelled. She sounded a lot older than she looked. "Sorry, you just looked really little. Didn't mean to offend you." She rolled her eyes and stood up. "It's fine, people make the mistake all the time. Let me guess, you thought I was 7?" She asked. I nodded, slightly embarrassed for making such an assumption without knowing.

She giggled at me. "Don't worry, you're not the first and probably won't be the last." Her voice was so sweet and she, from what I could see of her, was adorable. She has (H/C) hair, that was (H/L). She had these gorgeous (E/C) eyes, that shined as she spoke. This must be what love at first sight is. "Hey, what's your name? Mine's Sans." "I'm Y/N. It's nice to meet you Sans." She finished with an adorable smile. I was blushing at her cuteness, while she was walking away. "I've gotta go explore! Bye Sans! I'll see you around!" She said, waving her goodbye to me. "See ya, Y/N!"

~Y/N's P.O.V. 6 month time skip~

Today wasn't going very well at all. I was supposed to go to Sans and Papyrus' house, but my fox form wants to come out. I decided to do it in Snowdin Forest, thinking it would be secluded and no one would see me, but boy was I wrong. I was sitting by the Ruin doors, then decided to try and go deep into the forest to transform. I didn't have my beanie, or hoodie, so my tails and ears were extremely visible. As I continued walking past many trees, I heard someone yelling. I couldn't tell who was yelling, nor what they were yelling at or for, but hearing it reminded me that I didn't call Sans, and tell him I couldn't come over today. 'I don't have my phone on me, so I can't do anything about that now.' I thought as I continued.

Next thing I know, I hear someone walking towards me. I quickly run off, trying to make sure no one sees me. "Wait! Who are you!?" I hear a familiarly deep voice yell. It was Sans. He must have seen my footprints and followed me here, but how did he know I'd be in Snowdin Forest? I then, out of fear that he might have seen me, transformed into my kitsune/fox form. (In this form you are as big as a fennec fox) I jumped out from behind the tree I was hiding behind. "Wow, what are you? You look like a fox, but with five tails." Sans asks, obviously confused. I started to run off, slow enough for him to follow me easily.

~Small time skip~

I ended up running straight to Alphys' Lab and scratching at her doors. Alphys was the only one who knew what I really was. She opened the door, knowing it was me. "Y/N, wh-what are y-you doing h-h-here?" I pointed my nose towards Sans, who has been teleporting and running, trying his best to keep up with me. *Huff Huff* "Slow down, w-won't ya? W-wait, why are we at Alphys'?" He asked, looking confused. I nudged Alphys, telling her I was going to go to her hidden room. It's not the True Lab, but a room that Alphys made after Mettaton crashed through the wall. She nodded, trying to distract Sans from seeing me go in there.

~Sans' P.O.V. (So many P.O.V. Changes!)~

As I was trying to follow the fox thing, I saw it enter Alphys' Lab. "Y/N, wh-what are y-you doing h-h-here?" I barely heard Alphys stutter out. 'Wait, that's Y/N? There's no way?! Y/N is a human! Yeah she wears a big hoodie and beanie  to cover up her head and body, but she lives in Snowdin. What do you expect? W-why wouldn't she tell me? Doesn't she tr-trust me?' I thought. *Huff huff* "Slow down,w-won't ya? W-wait, why are we at Alphys'?" The fox, nudged Alphys and started to walk off. Alphys then started to walk closer, and started talking to me.

"S-sans? W-why are you h-here?" "I was following that-" I stopped, not knowing what the fox really was. "She's a K-kitsune S-sans." I nodded in understanding. "I was following the kitsune, when she ended up here at your lab? Do you know why that may be?" She nodded. "Sh-she's a c-close friend of m-mine." Once she told me that, I saw Y/N walk in with her hoodie and beanie on like normal. "Hi Sans! I'm sorry I didn't come over, something came up and I had to help Alphys." 

"Hold on, where'd the kitsune go?" I asked them both. "W-what kitsune?" Y/N stuttered. She sounded nervous, so I knew something was up. "Y/N, you know something and you're hiding it from me. What is it? I thought I was your friend?" I said, slightly hurt. 'I want to be more than friends though. I've known her for a while, and she's really pretty.' "S-sans, it's not that, it's just.... I'm afraid.... I don't want you to h-hate me, or think I look weird.... Like everyone on the surface did..." She had tears in the corners of her eyes. 

"I would never hate you, no matter what you look like!" I said, hugging her out of pure instinct. When I hugged her, her beanie slipped off of her head, but I didn't notice until I pulled away. I looked at her, seeing (F/W/C) ears, twitching every so often. "?" I looked at them, confused, but then it hit me. "Y-your the kitsune?" She nodded, taking off her hoodie, showing her five tails, swaying gently. "I think they look cute on you." 

She blushed and hid her face in my chest. I chuckled, holding her close. To neither of our knowing, Alphys is recording the whole ordeal, saying 'I ship it' and 'The ship has sailed'. I picked Y/N up and teleported to me and Pap's house. "Now you're gonna be my little kitsune.~" She then tried to hid her face even deeper into my chest. I chuckled and kissed her head. "I love you Y/N." "I love you too, Sans."

'~My Little Kitsune~'

(End of my first oneshot for this book! Yaaay! Hope you enjoyed!)