A/N: Ok so I finished the anime a few nights ago and needed to get this out. I'm still reading the manga though. This takes place after the last episode of the anime. I wasn't exactly sure how much time had passed from the beginning to the end of the show so I figured it was safe to say nine months to a year. Sorry if I am wrong.
Rin' POV
"You're not good at hiding things. Ever since that night something has been bothering you. What is it?" Yukio looked at me.
"You said that I was the only one who inherited the demonic powers. But that night, what happened?" I sat down in the chair next to him carefully as to not to smash my tail.
"I've tested myself everyday to make sure I was still human and not something like you. No offence. There was a dark mark that started to form on my shoulder and creep down my arm. Then the tests started to show positive. The night my powers awakened, that mark was down to my wrist. My powers came out in a similar way to yours Rin: during a time of extreme emotion. But by everything I've been told I shouldn't have these powers. My guess is that when we were in mother's womb the powers tried to take root in both of us but because I was too weak they transferred completely to you as father told me but they must have left something similar to a residue inside me that's been growing." He hung his head.
"Are you scared?" I blurted out.
"What do you mean?" He asked.
"Are you scared of yourself?"
"Rin I.." Yukio sighed. "Yes I am. I saw what happened in the woods when you lost it. I don't want to hurt anybody." He stared at me.
"Yukio, you know why I lost it. The Kurikara was cracked. That sword is like my heart. My power is sealed in it. That's why the old man told me to never draw it. He didn't want me to become what I really was. When they had me sealed up at the Vatican headquarters I was in a dream-like place. I thought I was dead honestly. But when you put the Kurikara on my chest, I heard a heartbeat, my heartbeat. It was weird." He gave me an odd look.
"Interesting." He said.
"There was something else I wanted to ask. Before I drew the sword the first time, I looked normal. No ears, no teeth, no tail. You have the ears and teeth but I haven't seen a tail on you. Did you not get one or are you hiding it?" I was curious.
"I finally learned something from you Rin." Yukio said as he slipped of his uniform jacket and untucked his shirt then pulled it up a little bit. A tail, lighter brown than mine was wrapped around his torso.
"Cool. But you shouldn't keep it wrapped around you all the time." I started waving mine around
"What? Why?" He seemed confused.
"Even though you can control it, if you keep it still all the time it starts to get a mind of it's own." I told him. "That and it feels good to have your tail out. Give it some air."
"Oh." Yukio uncurled his tail from his chest and waved it around, looking at it almost with wonder. It was a little shorter than mine. Then he started laughing.
"What's so funny?!"
"I always imagined the conversations we'd have when we got older. This was definitely not one of them." Yukio smiled at me.
"I've been dealing with what I am for about a year now. Is there anything else you want to ask about being this?" I asked.
"How do you deal with these things?" He pointed to his teeth.
"You mean the fangs? At first they're kinda annoying but you get used to them. Same with the tail. It'll get in the way for a while but the you'll get used to it. I actually like it. Just don't let anyone touch it unless you know that they mean no harm and trust them a lot. A demon's tail is it's weak spot." I pointed out.
"That's my next question, are we really demons?" Yukio sounded sad asking that.
"Technically yes. We have the blood of Satan in our veins, we look the part and we have the powers but that doesn't mean we're bad people. The demons that you guys face are harmful. We can use our powers to help which makes us different. We're good demons." I said as politely as possible.
"Rin, now that I know what it feels like to be you, I'm sorry." He looked at me with a depressing shine in his eyes.
"For what?" I was confused.
"When I told you to die. I, I was just angry after father's death and thought you were another dangerous demon who needed to be exorcised. Now I understand how wrong I was. Being this monster is just confusing." Yukio stared at me.
"Hey, come here." I stood up and spread my arms. He stood up and accepted my hug. "You don't have to be sorry for that Yukio. Just don't do it again." I held his shoulders and smiled. Then I slapped his face. "But don't call yourself a monster ever again!" I yelled. "You're my little brother and you need to know that no matter what you are, you're never going to be a monster and you'll always be my brother."
"Thank you Rin." Yukio squeezed me tight and silently cried. I hugged back and wrapped my tail around his torso to make a sort of double hug. Surprisingly he returned the gesture. A talk that I had meant to just be about whether he had a tail or not had turned into a deep conversation about what we were.