Anna Aoi, also known as Anna Saruwatari, is a central figure in the narrative. She is a high school student who aspires to become a robot pilot, a dream she has held since childhood. Her life is dramatically altered when she encounters the Mimetic Beasts, humanity's enemy, and seizes the opportunity to pilot the giant robot Neo-Okusaer.

Anna's personality is defined by her cheerful disposition and unwavering optimism. She is a spirited and devoted wife, affectionately calling her husband Goh by the pet name Goh-chin, though she is not afraid to engage in playful arguments to assert her views. Despite her youthful age of seventeen, she takes her role as a wife seriously and is fiercely protective, particularly of Lou, a young girl she and Goh adopt, embracing her role as a surrogate mother.

Her primary motivation is her love for Goh and her desire to stand beside him as an equal partner, both in their marriage and on the battlefield. Years before the story begins, Goh rescued her from a falling transport during a major battle, an event that sparked her admiration and eventual love for him. This deep connection drives her to secretly marry him and to fight at his side, despite his initial reluctance born from the trauma of losing a previous partner.

In the story, Anna serves as the pilot of the Neo-Okusaer and later its upgraded form, the Go-Okusaer. These robots combine with Goh's Dannar to form the super robot Godannar, making their cooperation and synchronization essential for victory. Her role is not just as a warrior but as a key emotional anchor for the team. Her secret marriage is publicly revealed during her first battle, forcing her to navigate her new life as a high school student, a newlywed, and a mecha pilot simultaneously.

Key relationships shape her journey considerably. Her bond with her husband, Goh Saruwatari, is the heart of the story, as they must balance their personal and professional lives. This relationship becomes complicated with the return of Mira Ackerman, Goh's former partner who was presumed dead. The revelation of Goh's past with Mira creates a significant emotional conflict for Anna, testing her trust and resolve. She also forms important connections with other pilots at Dannar Base, including a rivalry with Shizuru that evolves into mutual respect, and a close friendship with her classmate Sakura. Her maternal instincts are highlighted when she and Goh take in the orphaned pilot Lou, becoming her adoptive parents.

Anna undergoes significant development throughout the series. Early on, she is headstrong but insecure, particularly in her relationship with Goh. The emotional strain of learning about Mira and the near-death of a close comrade lead her to briefly retire from piloting and leave the base on a journey of soul-searching. This period of guilt and self-doubt allows her to mature. By the second season, she rediscovers her true calling as a pilot and returns to duty with greater confidence, taking control of the more advanced Go-Okusaer. She learns to put aside her personal rivalry with Mira for the sake of their mission, demonstrating significant emotional growth.

Regarding notable abilities, Anna is portrayed as a prodigy with a natural talent for piloting giant robots, which she demonstrates by intuitively operating the sealed Neo-Okusaer. She is also a skilled martial artist, referred to by the epithet the Beautiful Fighter. As a pilot, her primary ability is her perfect synchronization with Goh, which allows them to combine their robots and execute powerful attacks like the Spiral Fire and Heart Breaker as the combined Godannar. Her strength lies not in special powers but in her determination, perseverance, and ability to work as a true partner with her husband.