Ryu ga Gotoku Kenzan. is a side story within the Yakuza series, this time changing neon-lit Tokyo setting with a four hundred years older one: the city Kyoto of the year 1602, during the Edo period of the Japanese history. The player takes the role of the historical character Miyamoto Musashi, a renowned swordsman who, after the battle of Sekigahara, came to Gion district of Kyoto and changed his identity to Kiryu Kazumanosuke. Gion is a part of Kyoto where rich people indulge themselves in buying sexual favors. One day, a little girl named Haruka, comes to Kiryuu asking him to track down and kill an impostor pretending to be Miyamoto Musashi. At first Kiryuu refuses, but the girl's desperate attitude makes him reconsider and accept her plea.