Tasuke Tokugawa, son of the late Chief Engineer Hikozaemon Tokugawa, entered the National Defense Academy driven by the goal of serving on the space battleship Yamato. This opportunity arrived sooner than expected. At 18 years old during the events of 2205, assigned after training with the Academy's 38th class, he serves as an engineering officer in the Yamato's Engineering Division, holding the rank of Associate Lieutenant.

As the former chief engineer's son, he bears the weight of considerable external pressure. This burden is amplified by his self-proclaimed expertise in practical engineering skills, an assertion occasionally met with skepticism by others. Despite these challenges, he possesses a kind-hearted nature and demonstrates genuine concern for his friends. He navigates these expectations while pursuing his dream of becoming a fully qualified engineer.

His adherence to protocol is evident during a critical incident when fellow crew member Ryusuke Domon urgently requests engineering assistance. Tokugawa refuses to leave his post without proper authorization, expressing doubt that Domon acts independently. He only complies after Domon claims official permission, though Tokugawa openly questions the reasoning behind the orders.

His professional journey continues beyond this, ultimately leading to his promotion to Chief Engineer in the later timeline of Space Battleship Yamato Resurrection, realizing his aspirations and marking his progression within the engineering field.