Demon dogs are called Hanako (white) and Terunari (black). ^Got off google.
You're Megumi's girlfriend and has been for years now, he's only told one person, being Gojo since he went through his phone and saw both of your chats, so he was forced to explain, other than Gojo. No one else knew.
You had been discovered by Gojo as he was on a mission to deal with curses, obviously, and watched you very obviously, stare at the curse. Knowing you could see them he took you in!
You just arrived at the school.
Saturday. 8:22AM
Megumi, Yuji and Nobara was sat in the common room watching TV, Megumi had demon dogs out since Yuji wanted to pet them, which he was doing quite enthusiastically. Running his hands through the dogs snow white and midnight black fur felt magical to him, he loved those damn dogs.
Gojo walked in with you to introduce you to everyone, smirking to himself, already imagining Megumi's confused reaction. Demon Dogs sensed more cursed energy in the room and looked over to see Gojo, and you beside him. They recognized you since Megumi had shown them to you hundreds of times and they loved you. They both ran over immediately and barked at you.
Megumi was confused, he hadn't seen his Shikigami act like that with anyone but you, not knowing you was there he looked over and immediately was shocked and confused when he saw you which got a chuckle from Gojo.
Gojo: "You surprised Meggie-Boy?"
Megumi: "Don't call me that please-"
Gojo: "Well you surprised or what?"
Yuji and Nobara turned around and saw you, Nobara saw the uniform and immediately smiled widely seeing a new girl to hang with and not with Megumi and Yuji 24/7, Yuji just saw a new friend to make.
Megumi: "Well damn I'm surprised.."
Gojo: "Good because she's a new student!"
Gojo smirked at Megumi and pat your head.
Nobara: "What's your name girl? I'm Nobara Kugusaki."
Yuji: "I'm Yuji Itadori!"