Go Saruwatari is the main protagonist of the anime and a legendary super robot pilot known for his incredible skill in combat. He stands out with a tall, muscular build, standing nearly two meters in height, and has a stern, chiseled face that is often compared to a traditional heroic lantern jaw. Despite his intimidating physique and fierce expression, he typically wears glasses, which gives him a slightly softer look off the battlefield. His pilot suit is a form-fitting blue and white ensemble, which is his signature attire during sorties. At the start of the main story, Go is twenty-nine years old and has a notable fondness for sweet foods, a quirk that contrasts with his rugged appearance. He also has a younger brother named Shinobu Saruwatari.

In terms of personality, Go is a straightforward and blunt individual, often stating facts directly without decoration. He possesses a deeply passionate and hot-blooded spirit, especially regarding his duty as a robot pilot and protecting the people he cares about. While he projects an image of a fierce and courageous warrior, his personal life is quite disorganized, and he is often teased by his colleagues for his sloppy habits and his sweet tooth. His wife, Anna Aoi, gave him the pet name Goh-chin, a nickname that his comrades sometimes use to poke fun at him. Despite his heroic exterior, he can be argumentative and stubborn, which frequently leads to conflicts with Anna as they navigate the complexities of their new marriage.

Go's background is rooted in tragedy and heroism. Five years before the main events, he fought in a devastating war against the alien Mimetic Beasts alongside his then-partner and lover, Mira Ackerman. During the final battle, Mira sacrificed herself to defeat the enemy leader, leaving Go to grieve and live with the guilt of this loss. In the years following, he withdrew from active combat, relegating himself to mundane tasks like civil engineering and traffic control, which led many of the newer base members to dismiss him as unreliable. His life changed dramatically on his wedding day to Anna Aoi, which was interrupted by a new Mimetic Beast attack. He rushed to pilot his mecha, Dannar, while Anna inadvertently discovered and activated the long-dormant Neo-Okusaer. Together, they formed the combined robot Godannar and defeated the monster, unknowingly setting the stage for their future as a battle couple.

His primary role is as the ace pilot of the super robot Dannar, which combines with the Neo-Okusaer to form the mighty Godannar. He operates out of the Dannar Base, a key defense force against the Mimetic Beast threat. While he is the pilot of the core machine, the story focuses heavily on his developing partnership and marriage with Anna, who becomes the pilot of the Neo-Okusaer. Initially, he is extremely reluctant to let Anna fight, driven by a protective instinct born from his failure to save Mira. However, after witnessing Anna's determination and bravery, he accepts her as his official partner, and they learn to synchronize their hearts and wills to pilot Godannar effectively. The re-emergence of Mira from a long-term coma creates significant emotional turmoil for him, as he struggles with his past love for her and his present commitment to Anna, forcing him to confront his lingering guilt.

Throughout the series, Go undergoes notable development. He begins as a man haunted by the past, having closed himself off from piloting and true connection. Marrying Anna and being forced back into action becomes his path to healing. He must learn to trust a partner again and overcome his overprotectiveness. A significant low point occurs when he is defeated in battle, causing him to lose his will to fight. The sacrifice of a comrade, Shizuru Fujimura, reignites his resolve, teaching him that he cannot give up and must continue battling to prevent further loss. By the end of the story, he has fully embraced his role as a husband and a hero, having moved past his personal despair.

As a pilot, Go's notable abilities are substantial. He is considered a legendary ace with reflexes and combat instincts that are top-tier, handling the super robot with incredible precision even after a five-year hiatus from serious combat. He pilots the Dannar unit, which specializes in close-quarters combat. When merged with Anna in the Neo-Okusaer to form Godannar, they utilize the power of twin plasma drives to perform devastating finishing moves. A signature attack is the Heart Breaker, where Godannar envelops its body in flames and delivers a super-powered punch that crystallizes the enemy. The final attack is the Soul Breaker, a powerful kick fueled by all the energy from both drives. He is also shown to be capable of using the Godannar for rescue operations, such as deploying an airbag from its hand to catch falling civilians.