Alex

Family dramas which rely on similar tropes.
Rich male lead, poor female lead.
Disapproving parents, and bad blood between parents of the leads.
Male lead suffers from a regression type amnesia mid way through the show, resulting in him living as his younger self mentally for a while.
Multiple love interests and multiple side couples.

Down on their luck/poor female leads.
Male lead is from a rich family.
Female lead dumps male lead for reasons unknown to him. They reunite years later, where she now has a child- speculatively his.

Similar dynamics between mothers and daughters.
Mother left family due to father’s behaviour, never saw child(ren) again- until daughter is in trouble and asks for help from step father, who grants it.
Animosity between mother and child while step father tries to kindly close the relationship gap.
Mother seems to dote on daughter from new marriage opposed to caring for her original family.
Daughter is now a single mom herself, struggling to make ends meet.

Both star Park Eun Bin.
Female lead can see ghosts, and helps male lead solve mysteries/crimes.
Horror themes.

Fake family comprised of semi/former criminals and a down on her luck woman form for a specific goal and a good pay day.
Over arching conspiracy plot point.
Found family/slight romance progression.

Both about lead character returning to work after a controversy.
They become coaches to failing boys sports teams. Help get them back on track.
Romance subplots.

Both star Han Ji Hye.
Both ensemble family dramas.
HJH's characters in both are in very similar circumstances- unaccepted and looked down upon by her rich husband's family, recently separated from her husband (death/divorce) but still stuck in his working world. Her new romance also starts out on a similar bad foot (bickering/disliking dynamic).

Female lead approaches and befriends male lead with ulterior motives- regarding a toxic relationship with a mother/mistress.
Leads genuinely fall for eachother.

Age gap romance- younger woman x older man.
Ill female lead.
Hospital setting, doctor characters.
SFL has previous romantic ties to ML/SML.

Both star Iitoyo Marie.
Both are about a mysterious car accident from the main characters' teen days.
As adults they now try to heal and move on from it.

Time travel/loop thriller/mystery dramas
Reset leads live the same day over and over, KTIMNTN leads live the same 4 years over and over.
Slight romance.

Both star Ishihara Satomi and Iura Arata.
Workplace setting, somewhat of an ensemble.
Plot wise they are very different.