For example, there existed some sekai, such as "Taiheiki no sekai" (The World of "Taiheiki" [The Record of the Great Peace]), "Heike Monogatari no sekai" (The world of "Heike Monogatari" [The tale of Taira Clan]), "Gikeiki no sekai" (The World of "Gikeiki" [A Military Epic About the Life of Yoshitsune]), "Soga-mono no sekai" (The World of "Soga-mono" [the tale of Soga Brothers]) and "Sumidagawa-mono no sekai" (The World of "Sumidagawa-mono" [the tale of an apostate Hokai]).
例えば「太平記の世界」、「平家物語の世界」、「義経記の世界」、「曾我物の世界」、「隅田川物の世界」などがある。