Most of the flashback scenes that take place are actually scenes originally depicted in "Rurôni Kenshin: Meiji kenkaku roman tan" (1996), redrawn and re-acted to fit the more serious tone of the OAV.
The flashback to Enishi's revenge scheme in episode two was a major part of the final story arc of the Rurouni Kenshin manga. However, the television series ignored it completely. Thus, this is the only Kenshin anime production in which any scenes from the manga's revenge arc were animated.