The diary is now considered as a quite important historical source on the middle of the Muromachi period because Mansai recorded not only prayers as a gojiso of the Muromachi-dono (a priest who protects the public residence of the Shogun) but also the contemporary political circumstances in detail.
室町殿護持僧として祈祷だけでなく、当時の政治情勢が克明に記録してあり、室町中期の極めて重要な史料となっている。