A hard-working employee at a brokerage company, Yook Dong Shik (Yoon Shi Yoon) isn’t the type of guy who stands out in a crowd. Unassuming and quiet, with a timid personality and an inherent inability to stand up for himself, he’s the last person in the world you’d ever expect to experience anything exciting or unusual. But all of that is about to change.
Finding himself in the wrong place at the wrong time, Dong Shik plays witness to a gruesom murder. As if that weren’t awful enough, he happens to stumble upon the killer’s diary, a horrifying record of the heinous crimes committed by a clearly psychopathic serial killer. Terrified by what he has just witnessed and what he has just found, Dong Shik flees in a panic; but he doesn’t get far before he’s hit by the car of Sim Bo Kyung (Jung In Sun).
A member of the local police force, Bo Kyung is horrified by her involvement in Dong Shik’s accident; an accident that left him with two things: a horrible case of amnesia and a serial killer’s diary. Plagued by guilt, Bo Kyung finds herself being slowly drawn into Dong Shik’s life. As their stories entwine, Bo Kyung comes to make a life-altering decision: she must find the serial killer and bring him to justice.
There’s just one problem. With no memories of his past, Dong Shik comes to believe he’s the serial killer who penned that gruesome diary. As the days slip by, Dong Shik begins to make some serious personality changes, but can a man with such a timid past actually become a monster? And what of the actual serial killer? With no diary to ground him, it’s only a matter of time before this murderous madman strikes again.
An exciting mystery thriller, “Psychopath Diary” is a 2019 drama directed by Lee Jong Jae.