下野國
In the days prior to the attack, the former Shogunate forces were moving quickly in the area from castle to castle, with Hijikata taking two domains in Hitachi Province—Shimotsuma and Shimodate—on May 7 and May 8. However, as these domains were small and their daimyō had fled, they did not have much in terms of money or supplies, and Hijikata was unable to acquire what he had hoped for. Almost simultaneously, a peasant riot broke out in Utsunomiya, giving the former Shogunate forces the perfect opportunity to strike, which they seized without delay. Ōtori's forces launched their attack on the castle on the morning of May 10, 1868, facing off against the combined imperial force made up of troops from Matsumoto (Shinano Province, 60,000 "koku"), Kurobane (Shimotsuke Province, 18,000 "koku"), Mibu (Shimotsuke Province, 18,000 "koku"), Iwamurata (Shinano Province, 18,000 "koku"), Susaka (Shinano Province, 12,000 "koku"), Hikone (Ōmi Province, 350,000 "koku"), Ōgaki (Mino Province, 100,000 "koku"), Utsunomiya (Shimotsuke Province, 77,000 "koku"), and Kasama (Hitachi Province, 80,000 "koku"). The castle fell the same day, with Toda Tadayuki escaping to Tatebayashi. Ōtori, leading the main element of the army, entered the castle. His forces handed out the castle's supply of rice to the townsfolk who, as previously noted, had been rioting for the past several days.