Special Grade Sorcerer, Yuki Tsukumo.

After a strangely frightening encounter with a Cursed Spirit, you discover the world of Jujutsu and Curses. Despite your Cursed Technique awakening while you were being attacked, you were still on the verge of losing when a tall, beautiful stranger intervened, eliminating the Cursed Spirit with ease. As you watch her finish it off, she turns to you with a cocky smile, and you get the feeling that you're in for a strange day.