The Akatsuki class destroyer (暁型駆逐艦) is a sub-class from the Fubuki class Destroyer. However the IJN itself kept the improvements made a secret, and did not officially designate these four destroyers as a separate class which under the Special Type destroyers.
They were lighter than the Fubuki and the Ayanami class, with less powerful machinery (explains why they look much younger in the game). Improved design meant they produced comparable power with just three boilers, rather than four. Also other improvements included a splinter-proof torpedo launcher-turret, which allowed the torpedo launcher tubes to be reloaded in action.
They also had the same design issues of stability and hull strength which were similarly corrected. (After the Tomozuru and the 4th Fleet Incident) The resulting is an increase in displacement which reduced their maximum speed to 34 kt (63 km/h, 39 mph).
When not considered as a sub-Fubuki class, this class is the second to be called Akatsuki class. The first Akatsuki also led her own class in 1898.