石山本願寺
Two years later in 1578 at the Second Battle of Kizugawaguchi, Takakage was leading the naval forces again. The Ishiyama Hongan-ji was still under siege, and Oda's fleet, commanded once again by Kuki Yoshitaka, made another attempt to break the Mōri supply lines. Going against convention, Yoshitaka fought with six very large "ō-adakebune" ships, rather than a combination of small ("kobaya"), medium ("sekibune"), and large ("adakebune") craft. Normally, "adakebune" were essentially wooden floating fortresses, covered in gun and bow emplacements. According to some accounts, it may be believed that these six were the first ironclads, and were built such that guns could not penetrate them. However, rather than true ironclads, made primarily or entirely of metal, these craft probably simply had limited iron plating in key locations. Several Mōri vessels were burned and sunk, and Oda's fleet ultimately achieved victory. The supply lines were broken, and the Hongan-ji fell soon afterwards. However, during this battle an interesting flaw was discovered in the "ō-adakebune" design. As Mōri samurai rushed to board the large ship, all the defending warriors ran to that side of the deck, to defend themselves, and the ship capsized as its center of gravity shifted. Also in 1578 the "2nd Oda Encirclement Plan" falls apart when Uesugi Kenshin suddenly dies and the Ishiyama Hongan-ji monks made peace with Oda Nobunaga.