Movie
Description
Hyuga is a "Fleet of Fog" battleship, a reincarnation of the World War II Ise-class battleship Hyuga. Originally, she served as the flagship of the First Oriental Fleet before she was sunk by the submarine I-401 sometime before the events of the series. Following her defeat, her Mental Model, a humanoid avatar, chose to desert the Fleet of Fog and align herself with the crew of the I-401, joining the faction known as Blue Steel.

As a Mental Model, Hyuga appears as a woman in her early twenties. She has amber eyes and long, chestnut-brown hair that reaches her mid-back and curls inward at the ends. Her typical attire consists of a dark sweater under a white lab coat, often paired with a dark-gray mini-skirt and dark stockings. A notable feature is the monocle she wears over her right eye. Her physical appearance reflects her role as an engineer and technical specialist.

Hyuga's personality is defined by two primary traits: a deep obsession with technology and an intense, fervent admiration for the Mental Model Iona. As a self-described techno-freak, she is passionate about creating and improving various technological wonders, from upgrades for the I-401 to complex robots and cybernetic enhancements. This passion is physically represented by a unique construction of multiple robotic hands connected at their bases. This device is versatile, capable of acting as a floating work platform, curling into a protective egg-like shell, or shrinking to the size of a chicken egg to be stored in her lab coat pocket. Her dedication to Iona, whom she reveres as a goddess of war, often manifests as exuberant and physically affectionate behavior that borders on harassment. While Iona finds this behavior annoying and does not hesitate to defend herself, she still accepts Hyuga as a valuable and loyal ally. Despite her eccentric and often comedic demeanor, Hyuga is a sharp and competent strategist.

In the story, Hyuga first appears as the manager of the secret Blue Steel base on Iwo Jima. After her original ship body was salvaged for parts, she transformed the island into a fortified facility, using her engineering skills to create mining drones, a massive robot army, and other defensive structures. When the I-401 arrives at the base, Hyuga assumes a more active role, ultimately becoming a co-processor for Iona. In this capacity, she manages the I-401's high-end weapon systems, most notably the powerful modified Super-Graviton Cannon that was originally taken from her own hull.

Her key relationships are central to her development. Her devotion to Iona is her primary motivation, driving her to desert the Fleet of Fog and serve under Captain Gunzou Chihaya, whom she sees more as an obstacle in her pursuit of Iona's affection than a true commander, though she does accept his authority. She forms a notable alliance with the heavy cruiser Takao, with whom she often schemes to get closer to Iona or uncover secrets, such as the connection between the Supreme Flagship Yamato and Gunzou's past. Her former rank as flagship puts her in direct opposition to her former peers, most notably the battleship Kongou, with whom she clashes in fierce battles.

Throughout the series, Hyuga experiences significant development, evolving from a high-ranking antagonist of the Fleet of Fog into a dedicated and indispensable ally of Blue Steel. While her comedic obsession with Iona remains a constant trait, her role becomes more serious and critical in combat situations. She demonstrates immense courage and loyalty, such as when she single-handedly defends Iwo Jima against the onslaught of Kongou and Maya, putting her very existence at risk to protect Iona. Her actions prove that her feelings and sense of purpose have evolved beyond her original programming, embodying the central theme of Mental Models gaining independence through human interaction.

As a former flagship and a fast battleship, Hyuga possesses formidable abilities. Her original vessel was equipped with a powerful Wave-Force Armor, capable of withstanding an extraordinary amount of damage, including direct hits from corrosive warhead torpedoes. This defensive power is shown to be on par with that of the powerful battleship Kongou. Her arsenal includes numerous photon cannons, missile launchers, and a Super-Graviton Cannon. However, her most notable abilities in the series are technical, including her expertise in nanomaterials and her skill in engineering, which she uses to repair, modify, and create advanced technological systems for her allies.