Nagato leads the Nagato-class battleships, built under the IJN's 8-8 fleet program. She served as the Combined Fleet flagship until the Yamato-class arrived and was recognized globally as one of the "Big Seven" battleships permitted to mount 16-inch guns under naval treaties. Her appearance features long black hair, red eyes, and naval-inspired attire: a Japanese-style black-and-white top with yellow accents revealing her midriff, a short pleated skirt, metallic garter belts, and maroon thigh-high stockings. Distinctive headgear replicates her historical vessel's main tower. Personality-wise, she maintains a composed, professional demeanor, carrying underlying pride from her historical significance. Subtle hints suggest an appreciation for cuter elements, though she rarely expresses this openly. Interactions can reveal bashfulness, particularly concerning physical contact with her equipment. Her progression includes three forms: base Nagato, remodeled Nagato Kai (Level 30), and Nagato Kai Ni (Level 88). Each stage enhances combat statistics—firepower, armor, anti-air capability, evasion, and luck—while altering resource consumption and equipment. Her Kai Ni configuration equips a Prototype 41cm Triple Gun Mount, 10cm Twin High-angle Gun Mount, and Anti-torpedo Bulge. A defining Kai Ni capability is the "Nagato-class Special Attack," triggered under specific fleet conditions: Nagato Kai Ni must be flagship alongside another battleship (BB/FBB/BBV) in the second position, with six or more surface ships present and no submarines in six-ship fleets. Formations must be Echelon (single fleet) or Cruising Formation 2 (combined fleet). Upon activation, she executes two attacks followed by the secondary battleship's third strike; damage multipliers are influenced by equipped AP Shells and Surface Radars. Her quotes reference historical context, including her role as Combined Fleet flagship and participation in events like supplying Great Kantō earthquake relief in 1923. Wedding dialogue alludes to witnessing Operation Crossroads: "friendly and enemy ships, and that enormous light" before succumbing to radiation-induced sinking after the Baker nuclear test. Relationships emphasize her bond with sister ship Mutsu; their special attack voice lines demonstrate coordination and reliance (e.g., "Mutsu, follow me! First fleet, attack! Main guns, full broadside!"). As secretary ship in the anime adaptation, she manages base operations and communications, occasionally displaying protectiveness toward destroyers like Fubuki. Thematic elements associate her with the juxtaposition of naval warfare and daily life. Scenes depict her consuming large quantities of food for "refueling," participating in communal activities like curry contests, and utilizing onsen baths for repair symbolism. Her narrative underscores protecting ordinary existence from Abyssal threats, reinforcing anti-war themes through the value of normalcy.