In an attempt to destroy as many allied ships as possible, the Imperial Japanese Navy began arming their submarine fleet with manned torpedoes called kaitens.

The Action of 24 July 1945 concerns the battle between a convoy of U.S. Navy warships off Luzon and the Japanese submarine I-53 and her kaitens.

[3][4] In July 1945, the destroyer escort Underhill—under Lieutenant Commander Robert M. Newcomb—was assigned flagship of a convoy carrying United States Army soldiers of the 96th Infantry Division from Okinawa to the Philippines.

Underhill found the convoy off Buckner Bay, Okinawa on or about 21 July and, three days later the American ships were steaming around 250 mi (220 nmi; 400 km) northeast of Cape Engano and nearing their destination.

The kaiten were presumably manned by Sub-Lieutenant Jun Katsuyama, Ensign Toyooki Seki and Flight Petty Officers 1st Class Tsutoma Kawajiri and Masahiro Arakawa.

Two of the remaining American warships depth charged the area for an hour after Underhill was destroyed, but I-53 escaped and arrived back in Japan a month later, just before the end of the war.