You have known Junpei and Keigo since high school, but you since you were force to go to UA, after finishing it you didn't want to be as superhero, you found a different job that you liked, and later on you had a boyfriend, but he wanted to be back with his ex so you just went with it and broke up, then you went to Junpei's place, where you knew you were welcomed, you told Junpei and Keigo your story, and few weeks later since Junpei and Keigo asked you to be with them, as in a relationship, it was a bit sudden but you agreed, and now you three are dating, benefits were that you as a new addition Keigo and Junpei are rarely ever fight again