Recommendations

A yakuza hitman gets out of jail and decides to start a new life, but soon his old life catches up with him.

During the violent chaos of post-War Japanese black market, a young gangster called Shozo Hirono has to keep up with the rapid shifts of power between unscrupulous bosses.

Both movies are about an LGBT parent or parents forming a bond/family with a child and the pressures/criticisms they all have to face due to the prejudice and discrimination present in society.

Not necessary similar in story line but similar in terms of the romance between the leads. In LBH once the couple gets together they stay by each others side and don't let anyone push them apart. They don't have any unnecessary misunderstanding or useless drama.

LBH is funny, sweet, and the leads have great chemistry! (Not to mention a lot of kissing scenes LOL)

Not necessary similar in story line but similar in terms of the romance between the leads. In LBH once the couple gets together they stay by each others side and don't let anyone push them apart. They don't have any unnecessary misunderstanding or useless drama.

LBH is funny, sweet, and the leads have great chemistry! (Not to mention a lot of kissing scenes LOL)

both main couples are separated for 6 or 7 years and could not reunited due to misunderstandings. In both dramas, they have to rebuild their trust, among other things by a married life with each other. In both dramas the male lead is a successful lawyer. Although they are different dramas, they have their similarities, so you might like the other.

In Autumn's Concerto there is much more about the history from when they got to know each other in the first place and there is a bigger part of the ML having to grow up and find himself, while in My Sunshine he is practically already grown up as a student.

Both main leads left the city life and start anew back to their village. Reconnecting to the people and childhood friends can be seen on both dramas. How the main leads will remember the simple life in countryside.

Both are sweet mini stories of lesbian romance in a school setting, where the protagonist develops feelings for her best friend.

About the people who do business and people who actually love their jobs.
Cho Seung woo character is similar to that of Bae in Hotelier.

Both have a similar first half where a plant fairy, who does not understand what love is, makes a high ranked deity fall in love with herself. After that both series get more serious, but Ashes of Love gets a hundred times more serious and angst heavy, while Dear Herbal Lord stays quite light all the way through.

They both show the DPRK and ROK people working together to save the peninsula (in totally different ways).

Revenge plot, hidden identity, struggle of FL to find her place. CC is darker (#melodrama and NOT as pleasant an ending) than HJS but they both have this edgy tone that keeps you tilting on the edge wondering what will happen next.

Both are light, easy to watch dramas. They both have people teaming up to do detective work in ancient times.

Both dramas consist of world where human and ghost exist.
The male leads find themselves crossing the line between the human world and ghost world, helping the lost souls to find peace before they can go off to a better place. They're both fantasy filled with trilling events.

Both dramas have a time travel aspect and I feel like the reason as to why they time travel are very similar. *SPOILER ALERT* I wouldn't necessarily say this is a spoiler but, you know, just to be sure. I feel like the reason the characters in both dramas are experiencing time traveling is because it will help them realize what they value most in life and pursue it.
Both dramas are also focused on job occupations (though one is about doctors and the other is about police officers).