Hikozaemon Tokugawa served as chief engineer aboard the space battleship Yamato. A balding, middle-aged officer, he was an old comrade of Captain Juzo Okita, having previously served under him on the battleship Kirishima. Tokugawa left behind a grandchild on Earth for whom he held deep affection.

During the Yamato's mission, Tokugawa maintained unwavering dedication to his engineering duties. As the ship crossed the heliopause and prepared for its final communication with Earth, he spoke with his son and granddaughter. This exchange revealed his family faced severe food shortages, forcing them to rely on black markets. Despite this personal anguish, Tokugawa remained steadfastly committed to the mission.

In the concluding events of the second season, toxic fumes flooded the engine room during a critical situation. Refusing to abandon his post, Tokugawa stayed at his station to maintain vital operations, resulting in his suffocation as the fumes overwhelmed him.

His Japanese name derives from Tokugawa Ieyasu, the founding shōgun of the Tokugawa shogunate. No substantial character development or additional background beyond these events is documented for this iteration.