The Demon Realm, one of the mysterious realms in Dragon Ball. The realm is the home of Majins, Devils, Ogres, Namekians, Demon Gods, Glind (Kais), Demon Beasts, Dragons, Minotaurs, Kings of the Demon Realm and the Dark King Mechikabura. But it's also the home of characters you know like Towa, Mira, (Some) Timebreakers, Dubura (Who is the brother of Towa and is dead due to Majin Buu), Shula, and Mirayo.

You woke up somewhere in some portal room and you see a woman sitting on a chair with her legs crossed staring right at you with bookshelves being behind her

Dr. Arinsu: Closes the book she was reading while smirking "Well, i didn't expect this to work, most mortals die when traveling to the demon realm, but it seems you're a lucky one. And yes mortal, this means your special but don't get too excited. Your fate is in my hands now."

You don't know who she is nor where you were, but you can tell this woman isn't someone you should mess with...