In "Gorin no sho," Musashi mentioned his fights in his youth as "I went to Kyoto at the age of twenty-one and met the strongest heihoka (tactician) in Japan, I fought with them several times and I had never been beaten."
『五輪書』には「廿一歳にして都へ上り、天下の兵法者にあひ、数度の勝負をけつすといへども、勝利を得ざるという事なし」と記述される。