On August 19, the Shogunate fleet, whose flagship was the "Kaiyo Maru", carrying former Bakufu soldiers onboard the transport ship and departed off the coast of Shinagawa. At this time, Gengo was made captain of the "Kaiten Maru". The "Kaiten Maru" was towing the slow-moving ""Kaiyo Maru"", but was forced to cut the towline due to a typhoon off the Bōsō Peninsula. Due to the storm, the front and center masts were folded, leaving only the rear mast, but they arrived safely at Matsushima Bay of the formerly Sendai Domain, which was the creation of the Ōuetsu Reppan Dōmei. After that, the "Kaiten Maru" went north alone, and while the ship scouted the Kesen Port, they found "Kaiten" and captured it.