I found informations about Mito clan's school for the feudal domains - it was named Kodokan. Opened in August 1841. Any relations for later Kodokan of Jigoro Kano?
http://www.koen.pref.ibaraki.jp/foreign_language/en/kodokan/
http://www.koen.pref.ibaraki.jp/foreign_language/en/kodokan/