Yorimasa is a warrior who always had very good aim and used to shoot with his bow an arrow. Most warriors used Samurai swords but in this case he once saved an Emporer who was being attacked in his bedroom by this huge evil monster. He basically killed the monster with his first arrow and the Emporer rewarded him generously for saving his life and thats how he became famous.
To my informant, this legend appears very distant to her and although she is a native Japanese, does not believe in mythical creatures and therefore rejects the story as being the truth. She does believe however that Yorimasa like many warriors existed and that the story was simply embellished and that by the time it was passed down through generations had incorporated mythical creatures. The informant, who takes a keen interest in Japanese warrior tales finds this story particularly interesting in that she feels it says a lot about her culture and the portrayal of someone humble and heroic. Yorimasa, is present in several Japanese folk tales and that this is only one of many, or could be a combination of several. I discovered this interpretation to be quite accurate with a published version, which differs only in that it is more descriptive. I make the personal observation in that people who are from a certain origin but have never lived in that country, take an extremely great interest in their country of origins history and folklore and often religious beliefs.
Davis, F. Hadland. Myths and Legends of Japan. 1992. Dover Publications. Page 38