Spoiler

So I read this novel but very long time ago. Tbh, the novel is kinda drag on and repeating or retelling same stuff/incident over and over. Ok now the story.
The story is totally, just green flag story.
The king/emperor is married to many concubines but he isn't toxic or whatsoever, he just married them out of obligations and politics. This is not yin & yang / alpha omega. Just normal royal court story.
Uke was just a guard. Someday he tried to help a drowning male concubine, but he died instead. When he woke up, he is already in the concubine's body.
The male concubine is a son of influential minister. He was so infatuated with the emperor, he forced married the emperor using his father influence. The emperor treated him nicely, but the concubine was jealous person and he attacked other concubines and very defiant against the empress.
For context information, the story is mostly wholesome without any jealousy between concubines or any story "the emperor can only loves me".
Ok back to summary, after all bad things male concubine did, emperor finally hated him and stopped visiting him all together.
Now the guard woke up as concubine, he started acting nice which confuse everybody.
The emperor & other concubines actually thought he was just acting. So you have to be patience and it takes a long time to convince everyone that he is actually brand new person (the guard is nice person).
The emperor actually hated the concubine even more when the guard died. Because the guard was someone he recruited. The guard was someone poor and the emperor gave him chance to join as his soldier, I suspect the guard had a crush on the emperor.
Ok, so the empress is nice person. She is just and wise. She was the first person who actually believed that the concubine does changed after his fall into the pond. There is also young concubine who likes playing and visiting MC (after MC entering male concubine body), because she thinks MC just like his older brother. There is also a concubine who distrusted tge changed behavior and thought he was only acting. But during party, there is incident, if I m not mistaken, there is big hawk/eagle attacking the royal banquet, and MC protecting female concubine got attacked instead. The emperor, empress, and many concubines finally believed that he is indeed changed person. The emperor brought him to his palace to let MC recuperating. While MC was unconscious, the doctor said there will be huge scar on MC back. Emperor's wives aren't supposed to have scar or any blemish. So everyone thought that MC will be removed as concubine. Everyone think that is pity because MC is good person now. But emperor said it doesn't matter. MC woke up, and insisted to return to his palace. Empress said to all other concubines that she thinks emperor fell in love with MC. Which she thinks it's good thing because finally emperor have someone in his heart. The other concubines just agreed. Anyway the emperor started being nice to MC and all.
The novel is mostly just how MC trying to win everyone favors and prove himself as new man. Also, the real male concubine insisted to dress like a woman. He is beautiful, but he left his identity as male because he didn't like being overshadowed by female concubines. He was also rude to empress. But, when MC lives in the concubine body, he started wearing male clothing again and learn swordmanship. The male concubine's body is so weak so MC is having a hard time regaining his previous fighting abilty.
If you hoping for kiss, or sex scenes, they are faaaar away in the future. In the novel it's only happening on side stories after emperor fall in love with MC