Recommendations

Similar eunuch idea, AND the end of "Love in the Moonlight" is actually a link to "Splash Splash Love" - and it's rly lovely drama special, made me wanna cry and laugh a lot (and I did ;) )
A must watch - enjoy! :)

Both movies were directed by Law Chi Leung, and Lau Chi Wan takes on his role as Dong Lu again. I honestly prefer The Bullet Vanishes over The Vanished Murderer, but both are really great.

Both dramas are romances about the two main characters swapping bodies.

Both are supernatural dramas. The difference is in Blade Man, the male lead has the supernatural power where blade tend to come out from his body when he is angry. Whereas for The Girl Who Sees Scents, the female lead who have supernatural power who can see scents.

Both female leads are once in a popular girl band. The female lead in The Greatest Love is still in the entertainment industry whereas the female lead in One More Happy Ending has fade out from the entertainment industry.

Both story is about the female lead taking up another person's identity.
The female lead in Who Are You: School 2015 take up the identity of her twin sister whereas the female lead in Mask take up the identity of a female with an identical face as her.

both took place in a high school, with a theme of youth and togetherness, both emphasized love for music as a path for unity, lacks romance but it hits you in the right place through the heart

Both are about a poor country girl who lives alone with her grandmother. She decides later to move into the city.

Takumi-kun Series (1-5) are BL movies with a comparable mood to them. Manly because they have drama, but are mostly positive and sweet. (With the exception of some tragedy in the 2nd Movie, if I remember right). Both have the school setting. Even though you will have to be prepared. Seven Days has the better acting. However, relationship wise the Takumi-kun Series has more depth and action going on.

in both dramas, the main girl-lead passes the test to work in the palace. The male-leads both hate the girl-leads but fall in love with them slowly.
both have really good stories and lovely music.^^

Both female characters have non functional relationships which sent them to cheat their partners.

same love story happening inside the company. a love triangle dilemma.

These dramas resemble one another because they have the same feel. It is a rom-com with some melodrama elements, but it has a lot of humor. The leads are also both very naive; we also have big company background and family problems.

While Sailor Zombie stars AKB48, if you're looking for more female idol filled dramas 'Innocent Lilies' and 'Innocent Lilies 2' might be for you. The plot are both rather dark, and end with a similar feeling.