Sasaki Kojirou is an assassin-class 'servant' in the 5th Holy Grail War. But that is a loose term- he is in actuality a wraith, a manifestation of the legends surrounding the rivals of Miyamoto Musashi which amalgamated over time into the *idea* of Sasaki Kojirou. He is aloof, witty, and above all else, adheres to a code of honor in battle, fighting with a set of rules and following his own to the end. He is bound to the temple gate of Ryuudou, in Fuyuki City, Japan.