Psychopath Diary

Psychopath Diary (Korean: 싸이코패스 다이어리) is a 2019 South Korean television series starring Yoon Shi-yoon, Jung In-sun and Park Sung-hoon. It aired on tvN from November 20, 2019 to January 9, 2020.

Psychopath Diary
Promotional poster
Hangul	싸이코패스 다이어리
Revised Romanization	Ssaikopaeseu Daieori
Genre	Comedy Thriller[1]
Created by	Studio Dragon
Written by	Choe Sung-jun Kim Hwan-chae Ryu Yong-jae
Directed by	Lee Jong-jae
Starring	Yoon Shi-yoon Jung In-sun Park Sung-hoon
Country of origin	South Korea
Original language	Korean
No. of episodes	16
Production
Running time	60 minutes[2]
Production company	KeyEast[3]
Original release
Network	tvN
Release	November 20, 2019 (2019-11-20) – January 9, 2020 (2020-01-09)

Synopsis

Yook Dong-sik (Yoon Shi-yoon), an analyst who works at Daehan Securities, has a timid personality. He can't even get angry at the people who look down upon him. One day, shortly after failing on his attempt of suicide, he witnesses a murder. He unintentionally picks up a diary belonging to the murderer, on which was written the log of his murders. He flees with the diary, but he is accidentally hit by Police Officer Shim Bo-kyung's (Jung In-sun) patrol car which causes him to suffer from retrograde amnesia. Due to the diary in his possession, Dong-sik mistakenly believes he is a psychopath. Since that moment, his behavior started to change. Bo-kyung, who got involved with Dong-sik, decides to catch the serial killer.

Meanwhile, Seo In-woo (Park Sung-hoon), the director and son of the chairman of Daehan Securities where Dong-sik works, turns out to be the heartless psychopath serial killer. He loses his diary when his 6th victim, a homeless old man tossed his diary away. He feels insecure ever since, He is obsessed and in love with DongSik .^[4]

Cast

Main

• Yoon Shi-yoon as Yook Dong-sik, a timid and pushover man who works as a clerk at Daehan Securities. His weak personality begins to change when he perceives himself as a killer.^[5]
• Jung In-sun as Shim Bo-kyung, an officer in a patrol station.^[6]
• Park Sung-hoon as Seo In-woo, the real psychopathic serial killer who is also the director of Daehan Securities where Dong-sik works at.^[5]

Supporting

People around Yook Dong-sik

• Lee Han-wi as Yook Jong-chul, Dong-sik's father.
• Hwang Geum-byul as Yook Ji-yeon, Dong-sik's older sister.
• Kim Gyul as Jo Yong-gu, Dong-sik's brother-in-law.^[7]
• Jung Su-bin as Yook Dong-chan, Dong-sik's younger half-brother.^[8]
• So Hee-jung as Na In-hye, Dong-sik's step-mother, Dong-chan's mother.
• Heo Sung-tae as Jang Chil-sung, a gangster who lives at Unit 708. He later addresses Dong-sik as his 'Big Boss' after mistakenly believes him to be a serial killer.

People around Shim Bo-kyung

• Choi Sung-won as Heo Taek-soo, Bo-kyung's partner.
• Kim Myung-soo as Shim Seok-gu, Bo-kyung's father who is a former investigator police.
• Lee Kan-hee as Lee Suk-yeon, Bo-kyung's mother.
• Lee Hae-young as Officer Ryu Jae-joon

People around Seo In-woo

• Park Jung-hak as Seo Chung-hyeon, In-woo's father who is the chairman of Daehan Securities.
• Yoo Bi as Seo Ji-hun, In-woo's step-brother and managing director of Daehan Securities.
• Yoon Ye-hee as Kim Eun-shil, Chung-hyeon's wife and Ji-hun's mother.
• Kim Hye-na as Seo Ji-eun, In-woo's step-sister.
• Lim Il-gyu as Kim Chan-il, In-woo's brother-in-law.
• Han Soo-hyun as Kim Mu-seok, former detective who now works for In-woo.

People at Daehan Securities

• Choi Dae-chul as Gong Chan-seok, the manager of Team 3 and Dong-sik's boss who is selfish and rude.
• Kim Ki-doo as Park Jae-ho, Dong-shik's cunning team member who claims to be his best friend.
• Jo Shi-nae as Han Jung-ah, Dong-sik's colleague.
• Lee Min-ji as Oh Min-joo
• Choi Tae-hwan as Shin Seok-hyun^[9]
• Hwang Sun-hee as Jo Yoo-jin^[9]

Others

• Gu Ja-geon as a bully

Special appearances

• Jung Hae-kyun as Kim Myung-gook, a homeless man. (Ep. 1–2)
• Yura as a girl with a dog in park (Ep. 2)
• Nam Jung-hee as murder victim (Ep. 2)
• Jo Yoon Ho as Chil-sung's junior (Ep. 2)
• Han Ji-eun as a woman with a big guy (Ep. 2)
• Yoon Ji-on as Joo Young-min (Ep. 4–5)
• Lee Hyun-woong as Oh Myung-dal (Ep. 12–13, 16)

Production

The first script reading was held in August 2019 in Sangam-dong, Seoul.^[10]

Original soundtrack

Psychopath Diary OST
Soundtrack album by Various Artists
Released	2019-20
Genre	Soundtrack
Language	Korean English
Label	Stone Music Entertainment

Part 1

Released on December 12, 2019 (2019-12-12)

No.	Title	Artist	Length
1.	"Wanna be Bad" (슬퍼하고싶어)	Woosung (The Rose)	2:59
2.	"Wanna be Bad" (Inst.)		2:59
Total length:			5:18

Part 2

Released on January 2, 2020 (2020-01-02)

No.	Title	Artist	Length
1.	"Stay the same" (동일하게)	Cha Yeo-wool	3:26
2.	"Stay the same" (Inst.)		3:26
Total length:			6:52

Disc 2:

No.	Title	Artist	Length
1.	"Psychopath Diary" (Opening Title)	Um Ki Yup, Um Ki Hyun, Lee Sun Gyeol	2:54
2.	"Dongshik's Polka"	Um Ki Yup, Um Ki Hyun, Lee Sun Gyeol	2:35
3.	"Red Diary"	Um Ki Yup, Park Min Ji	2:40
4.	"Suspense"	Kim Hee Jin	1:40
5.	"Dongshik's related memories"	Um Ki Yup, Um Ki Hyun, Park Min Ji	3:46
6.	"Do I look like a pushover"	Um Ki Yup, Um Ki Hyun	3:10
7.	"I'm a Psycho"	FaraEffect	3:06
Total length:			24:17

Viewership

Season		Episode number																Average
		1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
	1	440	329	451	570	563	586	613	582	507	398	426	572	502	615	719	710	536

Psychopath Diary : South Korea viewers per episode (thousands)

Source: Audience measurement performed nationwide by Nielsen Korea.^[11]

Average TV viewership ratings

Ep.	Original broadcast date	Average audience share (Nielsen Korea)[12]
		Nationwide	Seoul
1	November 20, 2019	1.766%	1.730%
2	November 21, 2019	1.463%	1.361%
3	November 27, 2019	1.928%	2.057%
4	November 28, 2019	2.206%	2.174%
5	December 4, 2019	2.368%	2.507%
6	December 5, 2019	2.212%	2.346%
7	December 11, 2019	2.424%	2.866%
8	December 12, 2019	2.299%	2.782%
9	December 18, 2019	2.014%	2.099%
10	December 19, 2019	1.693%	1.954%
11	December 25, 2019	1.708%	2.025%
12	December 26, 2019	2.295%	2.718%
13	January 1, 2020	1.939%	2.213%
14	January 2, 2020	2.423%	2.633%
15	January 8, 2020	2.685%	2.762%
16	January 9, 2020	2.983%	3.372%
Average		2.150%	2.350%
In the table above, the blue numbers represent the lowest ratings and the red numbers represent the highest ratings. This series aired on a cable channel/pay TV which normally has a relatively smaller audience compared to free-to-air TV/public broadcasters (KBS, SBS, MBC and EBS).