Choi Ban Seok (CBS) is reincarnated as an ordinary person who works as an ordinary hardware developer in the R&D department of a dungeon called Hanmyung Electronics. He's been there for 23 years, clearing out a menial slime-level office monster.

Suddenly, he was transported to another world, where he encountered a new level of monster, Han Se Kwon (HSK). He was defeated and transferred to the lower level of the dungeon HR department, where he met Dang Ja Yeong (DJY), a frenemy HR manager (DJY). She is a hangman, and her main job is to cut off the heads of employees in the dungeon; the fewer the headcount, the more successful she becomes.

The story continues with CBS and his veteran adventurer friends battling monster bosses to clear levels in the dungeon; not to become the top adventurer, but simply to survive. Finally, he led an adventure group with some of his coworkers from the dungeon.

The story is realistic for an office drama, and the characters are similar to the coworkers and bosses I had. My brain, on the other hand, couldn't stop comparing it to isekai fantasy anime, which usually has a story about clearing dungeons to level up.

The drama crew is very talented at immersing you in the office situation and challenges, especially if you have worked with office politics before. Every time CBS is cornered by coworkers or bosses, you will become very emotional.

You must, however, be patient. It's a slow-burning drama, and it took me 5 episodes to become completely engrossed.