Haruki Oguma, the only son of AGS President Fuyuhiko Oguma, is selected to be an AQS Blademan operative despite his father's wishes for him not do so in order to prove that he can protect Fort Daiva City and its people by himself and not by his father's influence. His presence brings some doubt to the other veteran Blademen, including Saiki, due to his ties with the company's president. During an AGS operation to hunt down Gellis Bugmechs, Haruki receives orders to immediately withdraw. Despite this, he disobeys them and hunts down the Gellis with Saiki accompanying the young Blademan as they were able to defeat squads of Gellises on their own.
