I Stole the Number One Ranker’s Soul

Moa Son, an ordinary office worker, wakes up in a dungeon in the middle of the night and awakens as a collecting hunter. After barely making it out alive, she falls into the same dungeon but gets rescued by the first-ranked hunter, Jihan Seo, and becomes bound up with him. Now he’s offering to make her strong on this one condition -- "Promise me you will do your best to kill the bosses of all the dungeons that exist in the world.” Come again?
(Source: LINE Webtoon)