Lee Jae-ha has lived his entire life avoiding fights. With no particular dreams or talents, Jae-ha suddenly realizes he possesses an incredible natural talent for martial arts. Thinking, 'What's the use of being good at fighting...', he shows no interest despite his friend Lim Myung-in's persistent encouragement to try mixed martial arts. Without Jae-ha knowing, Myung-in secretly applies him to 'Never Back Down', a reality program that searches for hidden rough diamonds in martial arts...
**Original Novel:**
[Naver Series](https://series.naver.com/novel/detail.series?productNo=12729583), [Munpia](https://novel.munpia.com/463728)
**Original Webtoon:**
[Naver Webtoon](https://comic.naver.com/webtoon/list?titleId=855035), [Naver Series](https://series.naver.com/comic/detail.series?productNo=14729337)