The two ringleaders of the opposition to the Bakufu were from the provinces Satsuma (present day Kagoshima prefecture) and Chōshū (present-day Yamaguchi prefecture), two of the strongest tozama anti-shogunate domains in Edo period Japan.
In the morning of July 16, 1863, under sanction by Minister Pruyn, in an apparent swift response to the attack on the Pembroke, the U.S. frigate USS Wyoming under Captain McDougal himself sailed into the strait and single-handedly engaged the U.S.-built but poorly manned rebel fleet.