In 1858 when the Bakufu requested the Emperor to sign the Harris Treaty with the US to initiate trade with foreign countries including the US, Hisatada promoted cooperation with the Bakufu (Japanese feudal government headed by a shogun) and demanded permission to carry out the treaty.
1858年、アメリカはじめ諸外国との通商に際して、幕府が日米修好通商条約の勅許調印を求めてきた時、幕府との協調路線を推進して条約許可を求めた。