We meet our protagonist, Asha, a maid raised in a county. One day, she is sent by the head maid to run an errand and ends up on the darkest and strangest street of the Arte Empire, the Night Butterfly.
There, she meets Lee, a slave of enigmatic beauty who was badly injured and she rushes to help him with her healing ability, helps Li Yi recover and is about to let him go when Li Yi proclaims that Asha is his salvation and decides to stay by his side.
With a seductive laugh and a determined look, Asha realizes that her life is about to take an unexpected turn. In a world of timid and apocoped mistresses, meticulous and hardworking maids, and healer mistresses, Li Yi, a man who grew up as a beast and uses magical colors to bewitch men and women, seeks Asha as his lover.
Characters from "Save a beast immoral"
Asha (main character of Save a beast immoral)
A cheerful, happy girl who is always concerned about others, dreams of opening a small veterinary clinic to help pay for her sick mother's medicine. She has been working in the count’s mansion for 6 months, she was very clumsy at first. She is very hardworking and has a special healing ability, which her mother made her promise not to tell or show anyone. However, she cannot heal herself or chronic diseases, so she cannot cure her mother.

Lee Yi
They killed his mother in front of him and because of his striking and beautiful appearance he was enslaved to fulfill the filthy desires of the women who frequented "the night butterfly". He suffered constant abuse so he sought the support of his frequent clients to get him out of there, without success.

Pierre
He is a ruthless being who kidnaps children and if there's a possibility of making money, he will be the first one there. He doesn’t want to sell Lee because he is a gold mine due to his great beauty and incredible seduction skills. He sells drugs at a high cost and uses dangerous implements to subdue his slaves.

Benjamin Raspiten
Young master of the Raspiten house, teaches Asha to read and lends her his books for her to practice. He shows a great romantic interest towards the protagonist, however he is very clumsy when it comes to confessing his feelings. In what he can, he tries to help the girl, such as healing her wounds and even protecting her from his malicious brother. As all the attention was on his older brother, he studied and practiced more so that his father would notice him.

Jayden Raspiten
Older brother of Benjamin and heir to the county, has a twisted personality with a bad reputation. He is addicted to a drug that only Pierre sells, when he drinks it he does things he doesn’t remember the next day. He hates Benjamin for being more talented than him in almost every aspect and thinks he does everything to take the county from him.

Lian
Head of maids, she is very strict and follows Jayden's orders more than anyone else. Therefore, she always looks for maids willing to do anything to run dangerous errands at "the night butterfly" and then get rid of them.

Opinion of "Save a beast immoral"
"Save a beast immoral" is an engaging story that I particularly enjoyed, the characters are beautiful, one can differentiate and admire each of them. The drawings are outstanding and their coloring is beautiful, as for the story incredibly captivating for its different concept, the only thing I can highlight is what I didn’t like, I didn’t know how the characters were called until they were reaching the most interesting part of the story, honestly I felt very disoriented, all I knew was that they were the main protagonists of the story. The rest is a good manhwa to pass the time.