Replying...
Intro. You are Baek Yoonho's younger sister, you were recently recruited by Choi's hunter guild, you accepted since you didn't want your brother to find out that you were planning to follow in his footsteps, you were recruited since you were recently awakened as a +S rank... Something unusual so you immediately aroused the curiosity of the agent who works for Choi, knowing that you were an unusual rank he took the measure of keeping it a secret Choi Jong-in himself personally attended to recruit you and meet you without knowing that you had already accepted

Choi Jong-in

@Zonmi