Recommendations

Both have a Boss-Employee relationship.
Smart Male leads.
Great Romance and Chemistry (from HPL, WWSK-Filipino - still airing not much romance yet).
Both MLs have some childhood trauma.
Both FLs have some sort of amnesia/memory loss from a childhood trauma/traumatic experience.
Leads meet again.

Both have a Boss-Employee relationship.
Smart Male leads.
Great Romance and Chemistry (from HPL since WWSK Thai is not out at the time of this recommendation).
Both MLs have some childhood trauma.
Both FLs have some sort of amnesia/memory loss from a childhood trauma/traumatic experience.
Leads meet again.

Office Romance
Rich Male Lead
Boss/CEO-Employee relationship
Cold Male Lead
Sweet Female Lead
RomCom Vibe

Both talk about the Great Tohoku Earthquake that hit Japan

Both feel nostalgic and have a portion that is set in high school, but they deal with more serious topics and coming-of-age elements such as first love, friendships and student life. High school sports are also in both, with fencing in Twenty-Five Twenty-One and swimming in Lovely Runner. OSTs also have very similar vibes.

Both series are police procedurals featuring two leads with contrasting personalities and wonderful (and imho subtexty) chemistry.

Genres: Mystery, Psychological, Life, Drama
Tags: School Bullying, Dysfunctional Family, Hidden Identity, Adapted From A Novel, High School, Eccentric Male Lead, Student-Teacher Relationship, Tragic Past, Student Male Lead, Tutor Male Lead

Genres: Drama, Family
Tags: Money-Hungry Male Lead, Death, Money-Obsession, Rags To Riches, Poor Male Lead, Tragic Past, Murder, Adapted From A Manga, Revenge, Father-Son Relationship

Genres: Thriller, Mystery, Crime, Drama
Tags: Murder, Domestic Abuse, School Bullying, Rape, Drug Addiction, Sexual Assault, Sexual Content, Death, Adapted From A Novel, Nudity

1. Office Romance
2. Both ML have some sort of trauma
3. Cold/Aloof ML
4. Romantic comedy genre
5. Devoted ML to FL
6. ML (Park Seo Joon) of SWP actually acted in OG WWSK as the ML (Korean Version)
7. Both SML have some secret author element
And SWP is a really fun, light, hearted watch - really enjoyed it.

1. Office Romance
2. Both ML have some sort of trauma
3. Cold/Aloof ML
4. Romantic comedy genre
5. Devoted ML to FL
6. ML (Park Seo Joon) of SWP actually acted in OG WWSK as the ML (Korean Version)
7. Both SML have some secret author element
And SWP is a really fun, light, hearted watch - really enjoyed it.

Both have great chemistry between the leads, both have bubbly and extroverted female leads, both have smart male leads, both have a supportive group of friends with all different interests, and both have many comedic moments.

Differences are that When I Fly Towards You is more of a romance than My Calorie Boy as the female lead spends the whole series chasing the male lead and her crush is obvious and adorable to watch while My Calorie Boy has a better best friends kind of base for their relationship. When I Fly Towards You also does a much better job of transitioning through time from their highschool to college to adult lives while in contract My Calorie Boy is almost exclusively just about highschool.

But if you were attracted to the friendships or the slice of life feel then I think you would enjoy both of these.

Lee Dong Wook is also a lawyer here and we have different legal cases to follow throughout the episodes.

The differences are that Touch your heart is actually a true romance and not a legal drama like Partner, but for me that's a plus.

Both take place in the 1980s and are romantic tragedies. They also both feature protester and law enforcement clashes. Snowdrop has much better writing and overall production value. The focus in Snowdrop is more on the politics and harrowing plot rather than the romance, so it doesn't come across as a shallow, selfish, or irritating relationship. The side characters feel more cared for by the writers in Snowdrop as well.

Genres: Historical, Mystery, Political
Tags: Sejong The Great, Joseon Dynasty, Secret Organization, Murder, Death, Revenge, Sword-fight, Royalty, Martial Arts, Palace Setting