Recommendations

The male leads are really similar, both handsome but also mysterious and, at first, really odious with the female leads.

It's so similar: a clever and famous high school detective and a somewhat talented assistant (girl), who have feeling for each other but are shy to confess, solve mysteries

The story is pretty similar. The main character is considered not attractive compared to her sister and because of that her personality is shy and awkward. However, because she shares a name with the popular guy in her class she catches his attention. Because of her quiet demeanor she becomes the target of his bullying but things start to shift when she stands up to him. He still "messes" with her but in ways that create opportunities for her true personality to shine and in doing so they begin to fall for each other.

Main plot point shared is that the male lead doesn't like the female leads personality in the beginning but it soon becomes apparent that he misjudged her and he finds himself drawn to her.

Both have a female pretending to be a male. The main difference is the reason why she is disguising herself. There is a love connection, super confused guy trying to figure out if and how he could be attracted to another guy when he thought he was straight and working his way through that. This drama also has a bit more adult humor and romantic scenes so it's almost like Hana Kimi is the kids version (an awesome kids version might I add) and Coffee Prince is the teenage version.

Spring Waltz is a classic, older dramas and one of the famous Four Seasons. Although CITT is a comedy, it has some darker elements that remind me of the classic Spring Waltz. They're similar in the sense that they male lead id cruel to the female in the beginning and ignores her, making life tough. Later in the drama, they both come to realize they made a mistake and fall for the female leads. Both can be intense and misleading.

Both dramas are about over-protective mothers who go out of their way to do anything for their child and SAVE them. Although Angry Mom has some comedy tied up in it, there is a very dark underlying theme of corrupt schooling, abuse and bullying. Both dramas are MUST watches if you can handle the pain the mothers have to go through to save their children. Highly recommended.

Although these dramas aren't at all alike in storyline or theme, they're both fluffy, fun and light dramas that are feel-good romantic comedies. Both have very lovable male leads who fall head-over-heels for the female lead, both of whom are a bit ditzy, scatterbrained and ignorant in the field of what life has in store for them. Both dramas circle around the marriage theme and the characters' future. Both of these dramas are on my top 10 list and are very worth watching when you're in the mood for something super romancy and heart-pounding.

Both are revenge-based dramas in which the male lead is wrongly charged with murder and returns several years later with more power and tries to ruin his accusers. Both have strong female leads who are determined and can handle themselves without the help of a man. Both these dramas are melos and have a really sweet feeling and can get you sucked into the life of the characters immediately and of course.. both are very enjoyable. Although I must say that I prefered Beyond the Clouds more than I liked Goodbye Mr. Black.

While this movie is about a husband talking to his dead wife, Signal is a drama about a young detective using an old walkie talkie to communicate with a detective from the past and solve cold case murders.

Both take a place in Shangai during the 1930's. And the leading couple are similar: the rich and dominate guy with sweet and naive girl. Cruel romance is just more agresive, when the girl wearing tassel is more sweet.

Both dramas presents story about a girl who lives with some guys in one house and later she falls in love with one of them. But plot and atmosphere in these dramas are different.

Both dramas have well chosen cast, focus on historical side of story, more accurately, both stories are about fighting agains Japanese. Authentic mise-en-scene, stunning cinematography.

Sungkyunkwan's scholars help prince Sado's son to clear his father's name and find lost important document. It's totally different story, but you can learn another version of prince Sado's tragic story.
If you liked prince Sado as a history character, you should watch this drama. (from this drama I first heard about prince Sado and since then he is my obsession)

Both movies have similar atmosphere from old times, so you get to enjoy old korean music, see old clothes styles and, also, imagine how korean teenagers lived when they didn't have mobile phones! Both movies are about friendship, hardships and, of course, first love. But I could say that "Hot Young Bloods" isn't as sad as "Unforgettable", and, in my mind, has more 'dirty' languages :) And if you like Korean satoori (dialects) you should watch both movies and fall for main characters cute satoori.
Did I mention that actors are great in both movies? Yes, they are. "Unforgettable" has Kim Soo Hyun (The moon that embraces the sun, I miss you, School who are you) and D.O (It's okay that's love). And "Hot young bloods" has Park Bo Young (Werewolf boy, Oh my chost) and Lee Jong Suk (I hear your voice, Pinocchio, Doctor stranger, Secret Garden, School 2013) as main leads.

"Unforgettable" is set in 90s but shows how main characters are living in modern world. Like "Reply 1988", it's all about childhood friends which lived in a small village, and their first love and dreams.
Also, "Unforgettable" actors are really good. I could say as good as "Reply 1988". And, of course, in both you could hear old times music. Don't know about you, but I really love listening to korean music from 70s to 90s.