Recommendations

The stories themselves aren't that similar but I felt the vibe is. They are both cute dramas about high school students dealing with life and romance. Though romance is more central in Minami-kun no koibito: My Little Lover. Both also have light supernatural elements (time travel in Splash, shrinking in Minami-kun).

Both dramas deal with the psychological aspect of human nature as well as romance and life in general. MARS is a bit more deep and dark than It's okay, It's love but both are very good dramas. MARS is one of my absolute favorites, it's based on, and follows quite faithfully, the original manga by Fuyumi Soryo. I absolutely recommend you check it out! Like the phrase goes, it's an oldie but a goodie. ^_^

Similar vibe. nothing extraordinary happens but you keep watching one episode after another just for the atmosphere. both of them are lovely slice of life dramas.

This lakorn has the same main stars and I love Esther & Sean so much ???? I like the synopsis since I can somehow relate to Mami (Esther) ???? It is really a blessing in disguise for me that I have watched this ???? but anyway, this is a MUST WATCH because the chemistry is sooooo GREAT! I actually shipped Esther with Push but after watching this, guess I had a change of heart. ???? So yeah, watch this if you love Sake and Kate. ????????

Both have a female, which is a doctor. She travels into another world. The man from that world often travels to hers too.

Both have a Joseon man jumping into the present day and having to understand reality.

-Erased is also an anime that I highly recommend, since it would probably be less rushed than the movie. In Japanese, it is 'Boku Dake Ga Inai Machi'-

-both include male roles who are not the most popular in school
-both include time travel
-both are to save the death of a girl they like
-both have the sam vibes but erased is a bit more in the mystery category.

both are about time traveling and the two main male leads try to prevent events which are related to their loved one.

Both shows are costume dramas, and each have all the elements of a great story. There's tension that keeps you on the edge of your seat, laugh out loud moments of comedy, tragic elements, and a rock-solid romance. They also have chilling/compelling villains that are way too smart to be underestimated.

Tight storytelling, beautiful romance, compelling characters. Your emotions are about to go on a roller-coaster ride.

Both are hilarious takes on the procedural genre, both feature adorably quirky characters, and both have just enough subtext to keep you addicted.

Relationship between the two main lead is similar
The male lead personality is (talking about his rudeness and hidden kindness) quite similar

The way how the protagonist has to take care of the male lead is similar

Gives the same feeling
Tomboyish girl quarrels with the rude man
( might be I'm a bit biassed because both male leads are playing in Goblin)

Both the female leads has to protect their boss's (DBS in the beginning)

Although LNF follows the story of two adults loving after having a child, OMGB follows the story of the child and has similarities with both parents wanting custody. Both gave me similar vibes though, even if OMGB is much less romantic and much more slice-of-life melodrama-y (child had childhood alzheimers).