I read this manhwa a long time ago, probably back on Onemanga, and I just can't remember the name. It involves a lot of traditional Korean mysticism. The main character is this girl, who's pretty pure, then she gets this companion spirit guy. Time skip to when she's in college, and now she's kind of like a punk? She and the spirit solve some supernatural stuff...in the end, she ends up with this psychology professor, or some other kind of professor, and it turns out that in her past life, she loved two people or something, and her soul was split when she was reincarnated. The companion spirit she had, he had loved the other half of her spirit's incarnation, and was an incarnation of one of the people her past life had loved. The psychology professor was the reincarnation of the other guy.
Ummm, I hope that's enough? I'd really like to reread this, if I could. I'm not even sure if it's on Batoto, though...