He was the only feudal lord who joined the war other than the feudal lords from Kyushu except for envoys from the shogunate government, and this was due to his wartime career which was well received despite his age (seventy-five years old at that time).
これは幕府上使を除き九州の大名以外で唯一の参陣であり、老齢（当時75歳）にもかかわらず勝成の戦歴を評価されてのことであった。