I'll start by saying, I wasn't forced to watch A Frozen Flower, but it was hard to watch due to my background of childhood sexual abuse and a narcissistic parent who preferred either male or female.

The story: A teenage King who groomed a pubescent boy to be his lover in the guise of "service" to the King who was homosexual. Years later, the King needed an heir to keep his reign (or be killed). Disgusted at the thought of being with a woman, his Queen, whom he'd never consummated his marriage with, the King offered the services of his Chief Guard (his lover) to impregnate the Queen and hopefully no one would be the wiser. The Chief & the Queen fell in lust with one another (love?, NO.) after sneaking around behind the King's back well beyond the required "services" after finding their much needed freedom FROM the King and for both TO a first sexual encounter for both of them; she with her first lover and he with his first woman. They both were escaping a Stockholm syndrome situation with the King so they thought they "loved" each other. The King had the Chief's doonie cut off (castrated) in response to him being "betrayed" by the Chief & the Queen. The Queen had been impregnated so the King's plan did work, but now the King had to shut everyone up since too many people knew it was the Chief's dna and not the King who had gotten the Queen pregnant. The Chief, infuriated by not having a doonie anymore, and not having a future with the Queen, decided to kill the King. The King had also killed the Queen's maid and hung her head on a pike with the Queen's sachet (given to her by the Chief) making the Chief think the King had killed her. This gave the Chief all the more reason to kill the King. The Chief killed the King. The Chief was finished off by the other Guards and both bodies were to be hidden. The Queen could give birth to the throne's heir, and everyone could not live happily ever after. The end.

TL;TR: A gay King needed an heir, offered his longtime lover Chief Guard to service the Queen to impregnate her. The plan backfired due to the King not understanding people have emotions, and aren't robotic, thus he didn't contemplate his CG and the Q falling in lust with one another. Having lost control of his CG the King sought revenge by castrating the CG which prevented both he and the Queen from having a relationship with him in the future. The King was killed by the Chief. The Chief Guard was killed by the other guards. The end.

Korean films take leeway in explicit content, whereas their dramas don't.

SERIOUSLY, the movie should have a disclaimer attached to it (on Viki where I watched) as an EROTIC film, a Trigger Warning for sexual abuse (or grooming), pedophilia, explicit sexual scenes, nudity, profanity, & extreme violence, and restrict access for anyone under the age of 18. It also is not a BL movie and shouldn't be labeled as such. It is an adult erotic movie with adult content, plot, and storyline.