Recommendations

Both dramas have an "anti-hero" that hides his true identity.
Both dramas include the hero uncovering the truth behind his father's death.
Both dramas include the hero going against a high-profile organization.
Both dramas include action, romance, mystery and thriller all in one amazing cocktail.
Both dramas have somewhat of an open ending.

Both deliver a complete story - solid actors/cast - LONG - tactical/strategic power players - survival - revenge - LOVE.

-funny- fantasy- reincarnation- no memory of past-love triangle- Guy has supernatural powers.-They have a mix of comedy and seriousness while portraying a story with deeper meaning than just romance.

Both of them have the same genre and are from japan. It gave me a similar vibe when i was watching the murder of snow white.
and they both also have a very good stories and some plot twists on it.

Same actors, and the same theme from the last "death god's love'.
the difference is only in the roles (she's still an actress, but he's a lawyer, instead of being a police officer)

Both have got heroes from another planet .And have stayed behind for a reason.Both dramas have excellent comedy and romance.

Same type of story line rich guy ,poor girl and in between evil parents to separate them.Both are light hearted dramas and fun to watch

Although in Guardian the gay storyline is muted (in script, the visual language makes up for it heavily) Ossan's Love is similar in the aspect of the storyline revolving around the main character falling for another guy.

[There are no supernatural, or mystery elements in Ossan's Love]

It's literally the exact same plot, except the "music producer" in plant goddess is a "top actor" in Top Star U Back whose scandal has led his image to dwindle.

Same story line rich guy poor girl.Who is not scared to challenge the guy and turns the whole story into fun and loving .

Same related story btwn employee and employer.Same related story btwn employee and employer.Same related story btwn employee and employer.Same related story btwn employee and employer.

these are similar points in why secretary kim / Radio Romance :
comedy romance dramas
cheesy and comforting in a good way. Simple and cute
smart and hard worker FL
office work /entertainment work
ML is boss - FL is secretary / FL is beginner writer - ML is idol actor
childhood trauma / childhood friends
arrogant ML / kind of :) (popular and cold and proud ML)
rich man poor woman
ML chase FL first

"Masquerade" with actor Lee Byung Hun in it, was the movie that inspired the Kdrama "The Crowned Clown".

I think that these stories have relatively the same premise: two art students meet in college and fall in love but then separate for one reason or another. They then meet again in the future. Art in Love is definitely a more light hearted approach to this concept, while Where the Lost Ones Go is a melodrama version.

They both are about teachers using 'unusual' methods to convey a message about society to their students. They give very similar feeling and even have some scenes that remind one another. Some themes are also common to both, as bullying, for example.