Benkei Kuruma joined the Saotome Institute after Musashi Tomoe's death in the Dinosaur Empire conflict, becoming the new aquatic Getter Poseidon pilot for Getter Robo G. He fought alongside Ryoma Nagare and Hayato Jin against the Hyakki Empire. His background as a baseball player provided the physical conditioning necessary to endure piloting a Getter Machine. Muscular with messy dark hair, Benkei typically wore street clothes. His distinctive pilot suit integrated elements of baseball catcher gear. Personality-wise, he maintained a generally happy-go-lucky attitude marked by strong loyalty and protectiveness. He readily risked his life for endangered allies, though witnessing harm to animals or children could provoke intense anger. Benkei fought in numerous missions against the Hyakki Empire. Key actions included liberating Uzahra, where he helped repel attempts to steal the robot's head component and contributed to the space battle that destroyed the Hyakki fortress using the Shine Spark. He later joined the Great Mazinger and Grendizer teams against the Dragonsaurus, a prehistoric sea monster threatening Tokyo. Getter Robo G executed the decisive Shine Spark that ignited the creature's internal oil reserves, destroying it. Following the Hyakki Empire conflict, Benkei returned to the Saotome Institute. He aided in combating revived Dinosaur Empire threats using a prototype Getter Robo. During the Andromeda Country invasion, Benkei piloted Getter Robo G in Dragon formation underground. This mission resulted in loss of control over the machine, leading to his consumption by Getter Rays and subsequent death. This event profoundly impacted Ryoma Nagare, fueling his doubts about Dr. Saotome's Getter Ray research. Misa Ikari replaced Benkei as the Getter Poseidon pilot after his demise.