Bun'ō (文応) was a Japanese era name (年号,,nengō,, lit. "year name") after Shōka and before Kōchō. This period spanned the years from April 1260 to February 1261. The reigning emperor was Kameyama-tennō (亀山天皇).
1260Bun'ō gannen (文応元年): The new era name was created to mark an event or a number of events. The years of the Shōgen era was in a period marked by famine and epidemics; and the era name was changed in quick succession in the hope that this might bring them to a close. The previous era ended and a new one commenced in Shōka 3.
1260 (Bun'ō 1): Nichiren preached in the streets of Kamakura.
July 16, 1260 (Bun'ō 1, 7th day of the 6th month): Nichiren submitted a formal remonstrance to Hojo Tokiyori; this was the "Treatise on Securing Peace in the Land through the Establishment of True Buddhism" (Rissho Ankoku Ron)