Rider (ライダー, Raidā?) is a Masterless Rider-class Servant summoned by the Counter Force in the Strange Tales of the Imperial Holy Grail of Fate/KOHA-ACE. He is also able to be summoned by Ritsuka Fujimaru in the Grand Orders of Fate/Grand Order.
Rider's True Name is Sakamoto Ryoma (坂本龍馬, Sakamoto Ryōma?). The driving force behind the Satsuma and Choshu alliance, founder of the Kameyama Shochu (Later the Kaientai), and one of the patriots who worked towards the restoration of Imperial Rule and contributed greatly to the Meiji Restoration.
In Japan where the ‘Strange Tales of the Imperial Holy Grail’ war was held, he is a heroic spirit whose degree of fame rivals that of Oda Nobunaga, and a powerful servant with a peculiar type of mounted noble phantasm. To conceal his true name, he usually speaks in a fluent standard dialect, but at times his Tosa accent comes out.
His partner Oryou-san is not that historical individual, but a certain something that was sealed and bound to a certain mountain. In his youthful indiscretion, Ryouma pulled out the spear that bound her and released her unto the world.
Rider appears to be a middle-aged man with long hair tied back by a blue ribbon. He adorns a white suit with yellow buttons and shoulder pads, and a matching hat with a black band. At his side, he carries a katana and pistol.
An aloof young man in his mid-twenties. While a master of the Hokushin Ittou style of swordplay, he was a soft soul who disliked conflict by nature. A mysterious beautiful woman is always by his side.