See Genpei War and the Japanese version of the article Note that the translation here is very wrong The Japanese article s first sentence of the summary translated through Google Translate is helpful Kamakura period of Genpei battle in the motif j ruri that the theme of the success KeiKiyoshi action game it s not accurate but native Japanese speakers are referencing the fact that the game has a fictional reference to the conflicts that preceded the Kamakura period The rough translation on the front of the page doesn t make sense to me and Heike makes no sense at all