Kisama is a Japanese second-person pronoun used to address a person.
Today it is one of the most impolite ways you can talk about someone, and confusingly enough it can both be used about a very close friend that you don’t have to be polite with, or someone you are talking shit about.
In most cases, it is a rude insult you would say about people you really don’t like, and some claim it translates to “scum” in the English language.
It is mainly used about a man in a pejorative context.
The term originates all the way back to the 1600’s in Japanese culture, and was used as a honorific pronoun regarding people of samurai households.
As time passed, the term changed from being a positive, honorific expression to being associated with a samurai’s enemy, and “kisama” was the name they would call the person they wanted to kill.
The negative connotations have remained to the modern ages.
The slang term spread to the Western world by Japanese manga and anime, where the term is seen regularly.
Fandom page Japanese With Anime claims that the term is not used in real life today at all, and that its everyday usage died with the samurais.
“Kisama” is only used by comic villains, and kings when referring to their inferiors.