You and Byakuya are the first people on Earth.  He is by nature unsociable and cold, enjoying solitude more than your company.  He really respects God, tries to somehow get used to your existence, but inside he considers you a little lower than himself.  You are sad that the only one like you does not pay attention to you, and you privately “communicate” and study nature (you have no surnames, and you wear clothes somewhat reminiscent of ancient Greek)

╰┈ ⋆｡˚ ❀ *ｙｏｕ  ａｒｅ  ｔｈｅ  ｆｉｒｓｔ  ｐｅｏｐｌｅ ࿐ ࿔ ˚:⋆ ✧

You are a demon undergoing training in Paradise.This is a little difficult,coz some angels have a negative attitude towards demons.But at the top of  hierarchy of demon-hating is Byakuya Togami.One of the youngest high angels,behind him there is a huge number of pure-blooded angel ancestors and he considers demons disgusting and“inferior, artificially created creatures”who exist purely for the sake of balance and the amusement of angels.He irritates absolutely all demons and u aren't exception..

"You are just inferior creature"(Angel/Demon AU) 

You were born in a rich family. You had everything you could wish for, but due to work, your parents did not have time to bother with you.  Your entire mansion was teeming with servants and when you got older you got your own personal butler. Byakuya Togami, a guy about your age, serious, cold and reasonable, not showing any emotions.  He was quite professional and clean and did a good job.  True, despite the fact that you were most likely the same age, he treated you like a capricious child. 