Door Lock

Door Lock has been a favourite of mine for many years. I'd say it's more of a subtle thriller, where as Don't Buy the Seller (or Target) is more action packed and in your face. I do prefer Door Lock but while watching DBTS I found I was never bored, and quite frankly it seemed like a faster paced version of Door Lock in many ways.

Different storylines, however the concept of stalking is very similar.
Midnight is about the FL being stalked by a serial killer, whereas, Door lock is about the FL believing that someone is trying to enter her house.

both movie are about stalker who trespasses into someone else's home and meeting the consequences for it; though I find Door Lock to be more terrifying - as a woman living alone.

In both movies the plot focuses on a female main character who's trying to escape from a stalker/killer. They're quite dark and have some bloody scenes.

Kyung Min, a woman living alone in a studio apartment, becomes alarmed when she finds her door lock cover left open. After changing the password, she hears someone trying to unlock the door and calls the police, but they dismiss her concerns. Days later, with more signs of intrusion and a murder nearby, she realizes she's not safe and the police are no help. Determined to find the truth, she begins investigating herself, uncovering clues like fingerprints on the keypad and a cigarette butt near her door.

I found it very similar with when the camilia blooms because it has:
- the same actress
- the same scenario about "serial killer"
- close friends of the female lead get hurt because of her and get involved with serial killer acts

Both are south korean thriller films with horror elements that focus on a female main character. Her past experiences with men havent always been positive so shes rather concious about them. In both theres also a nice sismance. They share the same director so they have a similar vibe too and... this is a spoiler for my ordinary love story: ... theres a male serial killer in both.

Psycho dude methodically stalks a chick before kidnapping her. Definitely same vibes in both films.

Based on the Korean version which has the same synopsis of a woman living alone, who believes someone is breaking into her home.

Both are thrillers about home invasion, kidnapping and finding the killer. They have similar creepy vibe and built up tension.

The serial killers aren't similar, in fact Door Lock kind of has a lame ending, but 80% of the movie from the beginning is very interesting, both have a lot of suspence, feel threatening and both female leads end up killing the killer in the end.
In 'Door Lock' the serial killer is more gruesome.
In both the killer is obsessed with the female protagonist - but in 'Somebody' it's love, while in 'Door Lock' it's just another victim of stalking, obsession and not 'united by murder' at all.