Haruka Kaga pilots Rugger #7 for the Keets Team, the sea division that forms the super robot Kairugger. Her vehicle, the Aquatic Space Explorations Prober, constitutes the right thigh of the combined robot Dairugger. She shares a close friendship with fellow pilots Manabu Aki and Yasuo Mutsu. Her relationship with Manabu Aki is notably serious. She presents Aki with a lucky charm. This charm later appears with Telesu during his demise; he holds it while perishing in flames on Galveston, honoring his wish to stay there. The charm remains unrecovered afterward.