Added as part of the collaboration between Azur Lane and World of Warships, Azuma is a never-built ship based on one of Japan's Project B-65 proposals. The B-65 project was intended to create a "super-cruiser" meant to replace the aging Kongō-class battlecruisers and lead the IJN's cruiser squadrons into a planned "Decisive Battle" against the US Navy. Her purpose during such an engagement was to lay down heavy barrages against American heavy cruisers such as the New Orleans-class while being resistant to any return fire from them. While extensive design work had been carried out, no ships were laid down as Japan's focus shifted to replacing their extensive carrier losses and materials grew scarce.
As a shipgirl, Azuma is portrayed with dark hair and golden-colored eyes, along with animal ears similar to Takao and a sizeable bust. Her outfit consists of a jacket hanging off her shoulders, likely based off of an Imperial Japanese Navy uniform, a button-up shirt, a pleated skirt, and dark-colored pantyhose. Her personality is similar to Atago, being very "onee-san" and gently teasing the Commander.
As a reference to World of Warships, as per the collab, Azuma gains an ability based off of the "Demolition Expert" skill, increasing her high explosive damage and chance to set fires.