This fantasy drama begins with a love story between a young nobleman’s daughter Yoon Seo-hwa (Lee Yeon-hee) and mythical guardian spirit of Mt Jiri Gu Wol-ryung (Choi Jin-hyuk) that results in the birth of half-man, half-gumiho (nine-tailed fox) Choi Kang-chi (Lee Seung-gi). As the drama progresses, Kang-chi meets and falls for Dam Yeo-wool (Bae Suzy) and realises in order to gain her acceptance he needs to become human, and the way to do that is to find a book that will unlock the secret of doing just that.
| Also Known As: | Kang Chi, the Beginning, Gu Family's Secret, The Writings of Nine Houses, Book of the House of Gu, The Fox Family Book, The Love Story of Kang Chi |
| Directed by: | Shin Woo-chul, Kim Jung-hyun |
| Written by: | Kang Eun-kyung |
| Starring: | Lee Seung-gi, Bae Suzy, Sung Joon, Lee Yu-bi, Yoo Yeon-seok |
| Extended Cast: | Choi Jin-hyuk, Yoon Se-ah, Lee Sung-jae, Um Hyo-sup, Jo Sung-ha, Jung Hye-young, Yoo Dong-geun, Kim Hee-won, Lee Do-kyung, Jo Jae-yoon, Kim Dong-kyun, Jin Kyung, Kim Ki-bang, Kim Sung-hoon, Son Ga-young, Son Ga-young, Kim Hee-jung, David Lee McInnis, Song Young-kyu, Park Joo-hyung, Nam Hyun-joo, Lee David, Kim Bo-mi |
| Original network: | Munhwa Broadcasting Corporation |
| Original release: | 8 April 2013 –25 June 2013 |
| No. of episodes: | 24 |
| Running Time: | 60 minutes |
| Executive producer(s): | Lee Chang-seop |
| Producer(s): | Park Tae-young |
| Production Company(s): | Samhwa Networks |
| Source: | MBC |
