- Drama: On The Verge Of Insanity (English title) / No One But a Madman (literal title)
- Revised romanization: Michiji Angoseoya
- Hangul: 미치지 않고서야
- Director: Kim Keun-Hong, Choi Jung-In
- Writer: Jung Do-Yoon
- Network: MBC
- Release Date: June 23, 2021 —
- Runtime: Wednesday & Thursday 21:00
- Language: Korean
- Country: South Korea
Choi Ban-Seok (Jung Jae-Young) is a veteran engineer, working as a developer in the consumer electronics division of Hanmyung Electronics. He has a calm disposition and a warm heart. He also has a sense of humor, but he faces the biggest crisis of his 22 year working career. To avoid being caught up in a wave of dismissals, he is transferred to the personnel department. He is completely unfamiliar with the personnel department. He decides to survive in the personnel department and not quit this job.
Dang Ja-Young (Moon So-Ri) is the leader of the personnel department. She was promoted to the position recently. She is a workaholic and she wants to become the company’s first female executive. Choi Ban-Seok is a new member of the personnel department. She doesn’t know what to do with him, but her life slowly changes by working with him.