Board Thread:Questions and Answers/@comment-73.220.89.40-20150318192417/@comment-25977430-20150329010648

Vyrena wrote:

"According to a quarterly mook 艦これ鎮守府生活のすゝめVol.1 which was released in 2013, there are plans to implement new (Ukuru-class) escort ships, and because their displacement is less than that of destroyers, they would take a younger form, but they are said to be for the final phase of the war and thus, while they want to release it as soon as possible, they have told the fanbase to please be patient about it." (From the Easter Eggs page)"

IJN made lots Submarine Chasers towards the end of the War. That is the only Class with lower displacement than DD that was massively used for escort purposes.