The battle against Haruna and Kirishima begins with I-401 drawing them into a trap they set in the ruins of the old Yokosuka city. Although it fails to cause any significant damage, I-401 is able to circle around the two battleships undetected and launch a surprise attack using the now sunk Japanese battleship Mikasa as a decoy. However, Kirishima manages to avoid being hit and launches a retaliatory barrage of warheads. I-401 manages to barely avoid the attack. In an attempt to destroy I-401, Haruna and Kirishima join together and generate a huge gap in the water, trapping I-401 in the line of fire of their combined Super Gravity Cannon. Just before firing, however, they leave themselves vulnerable to Iona's last Erosion Torpedo which had been concealed inside Mikasa's wreckage. This triggers a chain reaction, destroying both ships. Haruna's mental model manages to salvage Kirishima's core and escape the ensuing destruction. The next day, a child finds the unconscious Haruna inside an abandoned warehouse.