In October 1200, when MINAMOTO no Yoriie, the Seii Taishogun (literally, "great general who subdues the barbarians") was having a feast (a drinking party) on a boat with young gokenin (an immediate vassal of the shogunate in the Kamakura and Muromachi through Edo periods) after holding a kasagake (horseback archery competition) on the beach of Kotsubo (near Kamakura), he ordered Yoshihide who was said to be an expert of swimming to show the skill.
正治2年（1200年）9月、小壺の浜で征夷大将軍源頼家が若い御家人たちとともに笠懸をし、船を出して酒宴を催していたとき、水練の達者と聞き及ぶ義秀にその芸を見せるよう命じた。