Knock Knock is a Korean webcomic screamer created by Studio Horang in 2015.
The webcomic begins by introducing Minji, a character deeply engrossed in typing on her computer. Her mother inquires about Minji's activities, who offers her cookies and recognizing her diligent work ethic. There's also a mention of Minji's father potentially being away on a business trip for a few days. The narrative unfolds against the backdrop of the summer of 2013. Around 1 a.m, a driver transports Minji to Seoul Station, where she's embarking on a journey to Japan for her art studies. Notably, before her departure, Minji requests the driver to place her suitcase in the trunk.
As the driver approaches Ok-Su station, Minji comes across the legend of the station's ghost. The Webcomic introduces a game called "Wall-knock ghost," where players summon a ghost and ask questions. Minji remembers about playing this game with friends during her childhood. The game involves knocking on walls until a distinct sound is produced, followed by using a pencil to predict answers based on how it falls. A brief silence ensues during the drive, broken by the driver's inquiry about the game's response. Minji's reply, "murder" serves as a evidential moment. As the story progresses, the driver reaches his destination, only to find Minji missing and a disturbing reveal inside the suitcase—a lifeless, bloodied Minji, accompanied by a screamer.
The narrative then reach into the subsequent investigation after the driver's call to the police about the suitcase. Key evidence includes security camera footage from a shopping mall near where Minji entered the taxi. The footage reveals both the individual who left the suitcase and the murderer. Later, a scene unfolds at Minji's apartment, where the driver, echoing Minji's actions, engages in the wall-knocking game. The webcomic ends with the same screamer along with a GIF depicting people's reactions to the webcomic.
NOTE: The following comic contains a screamer!