Recommendations

Both leads pretend to be the opposite gender.

Coffee Prince is a comedy romance and is very enjoyable to watch. You won't be disappointed :)

Both dramas concentrate on a specific culinary area.
Both teach you a lot about their respective domain.
Both revolve around a master in his field that is forced to accept an unwanted disciple - a headstrong woman, who gives her all to learn.
Both dramas are rather slow and have a certain "Indie" feeling about them.
If you enjoyed one of them, you'd enjoy the other one too.

Same vibe, similar setting with lessons about being true to oneself and some kickass fighting.
They both have male lead who are confused about their future, female lead who strives to be perfect and a guy friend who's timid.

These dramas share the same production team as well as a basis in the novels of Minato Kanae. Each deals with overlapping themes in a different way, though their atmospheres are similar.

Both stories based on the ghosts and dark magic. If you love stories of ghosts and dark magic you'll love them both. :) :)

both movies are an adaption from mangas and in the action / thriller genre

both movies are an adaption from mangas and in the action / thriller genre

terminal illnesses..... different ending but same feels... especially when in the hospital :))

Both are kdramas about personal growth with friends through music. One is kpop though, and Cantabile is about classical music. Both have an adorable ragtag group of music students.

A cop undercover for many years and he is thinking that this is the last job! This is identical, right down to the use of morse code and two opposing undercover (one good and one bad).

They obviously took the flashback and made an entire movie for the Japanese movie special from Internal Affairs II. The story is about a cop who has been undercover for over 10 years since finishing the Police Academy and only one person knows he is a cop.

Both movies have a taciturn lead whose armor gets stripped down by the girl.
Both movies are the story of two jaded people falling in love...

Though Cyrano Agency leans more on the romantic comedy side and Architecture 101 on the melodrama one, both deal with the bittersweetness of first love.

Both dramas deal with a couple getting married because of an arrangement and because the girl is head over heels for the guy. Though Wedding is more mature than than Sweet 18.

Wakamono Tachi bears a strong resemblance to Under One Roof to an astounding degree. There might be more siblings in Under One Roof, but those in Wakamono Tachi share the same issues as many of them (albeit mixed around). The eldest brother in each is a hard-working, lovable goofball who talks loud and fast. There's a lot of bickering at the table, a young sister having an affair with an older man at work, etc. But aside from these and other similarities, both are warm family dramas with a lot of heart and a good message. Plus, they each have "the cast of the decade," so to speak.