In Winter Siege of Osaka of 1614, Munenori served as a guide to lead the large-scale Tokugawa Army in Yamato Province; in Summer Siege of Osaka of the next year, he served as a personal bodyguard for Hidetada and in fact he killed seven soldiers to protect his master.
1614年の大坂冬の陣では徳川軍の大和国の道案内役を務め、翌年の大坂夏の陣では秀忠の身辺警護を務め、敵兵7名を斬り殺した。