In exploring the role of the oni in Japanese culture, I set out to determine to what extent oni are consistently described and how the depictions of them differ across various works. My basic methodology was to collect a number of varying sources and compare them, using background about oni and Japanese mythology as a way to give context to the set of works.
Lindquist, Daniel, "An Analysis of the Depiction of Oni Across Japanese Songs and Folk Tales" (2005). 2005 AHS Capstone Projects. 3.