21 August SHIP Japanese Merchant Cargo Ship 4, tons. Hiburi. 22 August SHIP Japanese Escort Ship. IJN. Ukuru Class. Built , tons. The Ukuru class escort ships were a class of ships in the service of the Imperial Japanese Navy Hiburi was torpedoed and sunk by the USS Harder on August 22, with killed and wounded. Shonan (昭南), constructed at Hitachi. The Mikura- class escort ships were a class of ships in the service of the Imperial Japanese Shimushu class escort ship · Etorofu class escort ship · Ukuru class escort ship · Hiburi class escort ship · Type C escort ship · Type D escort ship. The Etorofu- class escort ships were a group of fourteen ships built for the Imperial Japanese Navy during World War II. Eight of the fourteen ships were sunk. The Shimushu- class escort ships were a quartet of ships built for the Imperial Japanese Navy just prior to World War II. Contents. [hide]. 1 Background and. The Hiburi - class escort ship (日振型海防艦, Hiburi -gata Kaibōkan) was a sub class of the Mikura- class escort ships of the Imperial Japanese Navy (IJN), serving.