Destruction (2021)

Both main protagonists suffering from cancer can make contract with "devil" to get extra time to life. In If Cats Disappeared From the World can postman erase one thing from the world and then get extra day to life. In Doom at Your Service Tak Dong Kyung makes a contract with Myeol Mang for a hundred days to live how she wants, risking her everything.

Both the shows have supernatural persona involved. The core concept is same but the story and representation of characters are different.

This drama is a love story between Kataoka Sakuya, a grim reaper who comes to the human world for the first time, and Mochizuki Nayuki, a woman who lost her father at a young age and has devoted her life to raising her only remaining family—her younger brother. As they meet, they gradually come to understand each other, and slowly, they begin to fall in love. However, a fate that will dramatically change their lives awaits them both…

They have the same vibe. Both are supernatural and in both the main FL has a rather hard life. Filmed in an artistic way with good music and plot.

both female leads have only a certain amount of time to live and they are told that by a celestial being. they end up falling in love and it saves them in more ways than one.

Both FLs have their days numbered and both MLs have this type of 'scheduler/ neither human nor god' role. Both stories tackle the meaning of life and how to make the best use of your numbered days.

L, an angel who’s endlessly fascinated with the human world, gets into trouble when she unthinkingly saves the life of Han Shi Yeong, a man who was meant to die. To make up for her mistake she must guard him on Earth for one hundred days and keep him safe from Hwan, a death god who is required to collect his soul. Both supernatural beings must contend with the knowledge that whichever one of them fails by the end of the hundred days will be erased from existence, and the longer they stay on Earth the further their powers fade and the more human they become.

Both are fantasy themed dramas about male lead being creature from different world - god and grim reaper and human female lead.

I was really shocked how similar I found those two titles.
Not by story, but by aesthetics.
I thought, I was convinced, that those titles are connected by the same director and yet I was wrong which is amazing.
Still I think that JBL has better acting and music than DAYS (hehehe I just did ‘days’ while typing the shortage of the title, lol).
Yeah, but the vibe in DAYS is like mix of JBL and Goblin.

Yamihara Kokoro and Asada Toramatsu live in a town that is quite peaceful, until a serial murder case happened where the bodies all had their blood drained out. Five years have passed but the case remains unsolved. Meanwhile, Kokoro and Toramatsu have been in a relationship for a year, but are unable to get married as they are keeping a serious secret from each other. Kokoro is actually a vampire. However, she does not attack humans and live modestly. Toramatsu is a popular resident in the town and is trusted by many. After getting a divorce, Toramatsu got drunk and went back to his old house, where he met Kokoro, the current occupant. As the two continue to keep their secrets hidden, a horrific murder occurs once again in the town.

they don't have a lot of similarities but both are TvN dramas and both female leads have brain tumors and they are going to die
both are romantic comedies
both are on Netflix

If you like love stories between a mortal woman with a terminal illness and an immortal being, both have this trope. Doom is more slice of life though.

Human in love with personification of death or destruction, hospital setting, melancholy feeling, focus on plants/growing things.

Different in tone but similar in characters and aesthetics. ML is a god like being, FL a human, and their relationship grows slowly. Also in the end, ML disappears, then returns as a human.