No Ninja is interpreted in colorful ways in fiction more than Fuma Kotaro (風魔 小太郎). For instance, in novels, comics, and games the ninja characters in history have characteristics that are quite defined. The role of Hattori Hanzo (服部半蔵) is generally always as the boss of ninja groups and Sarutobi Sasuke (猿飛 佐助) is on the whole a young, active and orthodox ninja. Fuma Kotaro though has various type of characters. Sometimes Kotaro is portrayed as a bad guy, a rat, and as an artist. At other times he is a babyface, nice guy, and leader of a ninja community.
What is the reason for this phenomenon? It is because the legend of Kotaro is very mysterious. There are some possibilities that the ninja Fuma Kotaro did not exist because there is only one historical document which describes about Kotaro as a ninja. It is " Hojo-Godaiki (北条五代記) " in which stories about the Hojo-family (北条氏) are written. The Hojo-family was a Daimyo (大名) under whom Kotaro worked. It is quite natural that we do not have many records about ninjas so I am going to tell you about Fuma Kotaro as a ninja according to the historical documents available.