I have little knowledge of the Japanese language and am easily confused but this is similar to English translation I found and the Kanji at and the Saohe Gujo link
I am guessing “Gujo Tone” has something to do with the historical style of Tenkara from the Mino Gujo area
http://www.hi-ho.ne.jp/amago/b-streams/flytying/tenkara.html