Recommendations

both have similar plots about a girl in love with the school's genius who is cold and indifferent. There is also the development of friends over the years, from school to after college.

First set in high school with old school technology. Although On Your Wedding Day is not set as far back as Reply 1988.
Also first love, more than first loves, realistic moments of choices and decisions we make on our journey of life.

Adult romance and realistic story
Both dramas have strong leader females and a serious tone
Both dramas have affairs

It has a similar plot line and both are slice of life dramas -each episode has its own conflict to be solved (in It's Okay to Not Be Okay, the conflict of the patients staying at OK psychiatric Hospital and in Hotel Del Luna, the conflict of the wandering spirits )
The romance also progressively develops in each episode.
Both have similar main leads, ML leads a closed off life, while FL is hot-headed, not afraid to speak their mind, can be a badass, fashionable af.
Both the dramas also have good/similar aesthetic appeal and OSTs

Cold Male Lead
Bright and pleasant female lead
The female lead goes through a tough time in the beginning and her life starts to turn for the better after meeting the male lead.
Love triangle
Co-habilitation etc. you get the gist right :)

Political Based Shows
Centered around the arc and growth of the female lead who goes from someone who is under the depth and grows into their roles
Romance with her co-worker
Witty Dialogue and Banter
Father-Son Relationship Quarrels

It's the same type of webtoon humor following ridiculous adventures. It's also slice of life and centered around familial relationships.

Both series have romance between a warm, level-headed doctor and a cool military man. There also have bandits and military missions.

- the leads' personalities resemble one another: both female leads are bubbly and passionate, while the male leads are geniuses with a cold personality
- the male lead falls first, and although there are initial disagreements, gradually they begin to notice the other and the romance develops from there
- even the female leads' faces and styling are similar

Both are set in a hospital type setting. Both have main characters that have truama in there childhood. They work to over come that truama through the help of someone who cares about them.

They are both psychological dramas in which the ML holds back his feelings to protect everyone around him. The difference is that one's about a psychopath serial killer father and the other is about a antisocial personality author.

Similarities in the story:
- FL has a habit of telling lies, with the ML allergic to lies. - - MC end up living together
- She worked as his assistant/secretary
- SML has a shared past with FL, however brief
- Dysfunctional parent/child relationship

A female lead whose being punished by the heavens due to an incident in her past must face up to it in the present day with the help of a soft, slightly clueless but very loyal human. — a description that fits both dramas perfectly! Though their personalities are very different, both women have a tendency to be hot-headed in common along with good leadership and addictive personalities and excellent clothes.

Though the overall story is different, the atmosphere is extremely similar with the long-suffering lead and their sense of being overwhelmed and trapped by everyone around them. The villains in both dramas are also equally horrifying and nightmarish.

Both focus on prosector leads who are aiming to take down corrupt people in power. The main lead (Hwan Shi Mok in Stranger & Jung Geum Ja in Hyena) have an unconventional approach to their cases and tend to rub people up the wrong way. [also in both shows their partners are the ones who understand them best]