- 'Title:' 김비서 가 왜 그럴까 / kim biseo wae geureolkka
- 'English Title:' What's Wrong with Secretary Kim?
- 'AKA:' Why Secretary Kim
- 'Genre:' Drama, Comedy and Romance.
- 'Episodes:' 16
- 'Original network:' tvN
- 'Original release' 06-June-2018 to 26-July-2018
- 'Runtime:' Wednesday and Thursday 21:30
- 'Soundtrack:' What's Wrong with Secretary Kim? OST
Lee Young Joon has the perfect appearance and skills, he is the vice president of Unique Group, he has always had secretary Kim Mi So, but one day she decides to quit his job, in that moment he realizes how much he needs Miss My So.
'Young Joon's family'
- Kim Hye Ok as Madame Choi (Mother of Young Joon)
- Lee Soo Kyung as Madame Choi (young)
- Kim Byung Ok as CEO Lee (Father of Young Joon)
- Go Se Won as CEO Lee (young)
'People close to the house Kim'
- Baek Eun Hye (백은혜) as Kim Pil Nam
- Heo Soon Mi (허순미) as Kim Myung Hee
- Jo Duk Hyun as Father of My So
- Lee Min Ki as father of Min So (young)
- Jung So Min as mother of Min So
'Personal of the company Unique Group'
- Kang Ki Young as Park Yoo Sik
- Hwang Chan Sung as Go Gwi Nam
- Pyo Ye Jin as Kim Ji Ah
- Lee Yoo Joon as Jung Chi In
- Hwang Bo Ra as Bong Se Ra
- Lee Jung Min as Lee Young Ok
- Kim Jung Woon as Park Joon Hwan
- Kang Hong Suk as Yang Cheol (Secretary of Young Joon)
- Kim Ye Won as Seol Ma Eum (Secretary of Yoo Sik)
- Hong Ji Yoon as Oh Ji Ran
- Park Byung Eun as Park Buyng Heon (cameo, ep.3)
- Lee Do Yun (cameo, ep.4)
- Seo Hyo Rim as Park Yoo Sik's ex-wife (cameo)
- Based on the novel and the webcomic of the same name 'Kimbiseoga Wae Geureolgga' by Jung Kyung Yoon.
- The first script reading was carried out on April 10, 2018.
- In the chapter 2 in the karaoke they sing the song BBoom BBoom of M OMOLAND and Mr. Chu of Apink.
- The house of the character of Park Seo Joon is the same one that used the character of Hyun Bin in the 2010 drama Secret Garden.
- The actors Park Seo Joon, Pyo Ye Jin and Hwang Bo Ra had already worked together on the drama Fight For My Way.