The failed Miyako Bay raid for Kotetsu

Although the Tokugawa shogunate had bought the ironclad, the United States delivered it to the imperial side, making it the decisive prize in the final campaign. Three Ezo ships set out to seize her, but weather and machinery trouble left only the flagship Kaiten ready to attack on time. Kaiten approached Miyako Bay under an American flag, then attempted a ramming and boarding assault after revealing the Ezo colours. The collision left the attackers trying to climb roughly three metres from a lower deck and limited how many could board at once. Kotetsu's Gatling gun then swept the approach, forcing Kaiten to withdraw with casualties.