During feudal Japan, there were samurai - noble fighters, equipped with a katana (sometimes other weapons) and heavy armor, who stood up to protect their daimyo (as feudal lords were called in Japan). Due to very strict and cruel concepts, the samurai was not afraid of death, and the warrior who could not fulfill his destiny usually committed seppuku (committed suicide).
Despite the fact that the image of the samurai in some games is highly romanticized, such a setting has a huge number of fans. There are not many games about samurai, but recently feudal Japan has begun to gain popularity again: proof of this is Nioh 2, Sekiro: Shadows Die Twice and the upcoming Ghost of Tsushima.
Sometimes magic and fantasy find a place in games about samurai: then ancient warriors have to fight monsters from Japanese legends and fairy tales, including dragons and other creatures.