was a after Bun'ō and before Bun'ei. This period spanned the years from February 1261 to February 1264. The reigning emperor was .
Change of era
- ; 1261: The new era name was created to mark an event or a number of events. The previous era ended and a new one commenced in Bun'ō 2. The era name comes from The Political Program of the Zhenguan Period and combines the characters ("broad") and ("long").
Events of the Kōchō era
- June 11, 1261 (Kōchō 1, 12th day of the 5th month)<!-- NengoCalc
弘長一年五月十二日 -->: Nichiren was exiled to Itō in the Izu Province.
- March 19, 1262 (Kōchō 2, 28th day of the 11th month)<!-- NengoCalc 弘長二年二月二十八日 -->: Shinran passes away at the age of 90
- April 1, 1263 (Kōchō 3, 22nd day of the 2nd month)<!-- NengoCalc 弘長三年二月二十二日 -->: Nichiren was pardoned.
