Kyuden Toketsu (CB21) was founded by Yasuki Toketsu an extremely wealthy Yasuki merchant who wanted to retire in comfort around the year 1050. It was not until 1060 that he discovered the nearby monastery where the monks remembered the sacrifice of Kuni Harike, who sacrificed his life to imprison the Kusatte Iru. The castle itself was located near the Plains of Foul Tears between the Spine of the World Mountains and the Twilight Mountains, in a place which would become part of the Toritaka province.