Recommendations

I am surprised nobody recommend this they have very similar feeling
the story is around the three women and their lives, the romance.
Each of them are different and are in great relationship like sisters.
Both stories are funny and deep at the same time.
You can relate to scenes thinking 'same' or 'mood' or are just reminded of you and your friend.
Both are easy to watch.
I also recommend other seasons of I need romance (it isn't continuing series but same type series with different friends and stories).

-Both female leads came from a rich family without originally knowing themselves
-Both female leads fell in love with their butlers

Both series are a continuation of one of the couple from a beloved series that focus on their post high school lives.

Both about an older sister trying to protect/save their younger sister from a kidnapping.

Description of Manhole:
A serial killer has been terrorizing a neighborhood in Seoul, and in the span of 6 months, 10 people have disappeared without a trace. He uses a manhole to trap his victims. His latest abductee is Soo Jung, a 14-year-old girl, and her older sister Yeon Seo is desperate to find her before time runs out.

If you enjoyed the male lead Yang Yang, the computer game aspect, and the strong friendships of Love O2O then you should really watch The King's Avatar. Yang Yang plays the male lead of this drama, and they are similar although not exactly the same. The gaming aspect, which was a huge part of Love O2O, is also a huge part of The King's Avatar. And of course, there are so many strong, healthy friendships in The King's Avatar just as there are in Love O2O. Of all the shows I've watched so far, I think The King's Avatar is the most similar in vibe.

Both dramas combine sport and business themes into one, and based on novels of the same writer. The plots are different though, where Roosevelt Game has "parallel sport-business story" but No Side Game is a more directly connected sport-business kind of story.

both have different plot but both are same in huge conspiracy like bluehouse-bomb-blast/plane-crash which involve higher authorities. which Shock the main characters as they investigate, reveals the truth they had not even expected/imagine . both story goes around blue house , country president, national investigation service and both have Female Lead NIS agent

vagabond is more action packed drama than designated

both about a group of youth that investigate crimes/mysteries. Both set in a historical period, tho young blood is set in a much earlier time period.

both set in wuxia historical era. Strong female lead skilled in fighting, both male and female lead are very smart.

Both series are a continuation of a beloved series that focus on either the outcome or snippet of a day/week of one of the BL relationships.

Strong female lead character. Desipte being in historical times, both female and male lead are highly intelligent and scheme against each other, but become romantic interests in the end.

female characters are strong and badass. Both are about an organisation that sends people to uncover mysteries/ do jobs set in historical times. Eventual romance between certain teammates. Young blood is about a government spy orignisation however, wheras bloody romance is about assasination jobs. young blood has a team of main characters whereas bloodyromance has only the two.

Both has badass female characters and intelligent youngsters. Both about a hidden spy academy run by the government. Both about mystery/investigation but imo young blood is more cleverly written and has more intelligent chararcters. Plough department is a bit more silly, but young blood also has lots of comedy.

They are both short films about a vampire and a mortal, one is more like a movie though. TVLND has some romance, but not much happens since it's so short, BV is all romance.

both have tragedy relating to the male lead
both are revenge dramas
ML lover (/ lovers family) cause of tragedy