Despite holding impressive qualifications and a diploma from a well-respected university, Kang Yoona is having a tough time securing employment. After getting frustrated from sending numerous resumes, she decided to treat herself (if you catch my drift). However, upon finishing, she discovered an unusual man gazing at her. The man, Kyle, was revealed to be the CEO of a start-up located in the underworld, and Yoona unexpectedly found herself working there under a short-term contract. On her first day, Yoona and Kyle crossed paths at an enigmatic hot spring situated in Ulcheon Mountain, deep within the realm of Hell...