Kensaku Shiraishi is a skilled scientist and combatant who served as the original second-in-command of the Battle Fever team. As Battle Cossack, he wielded twin sais and performed a traditional Cossack dance during the team's roll call.

Tragically, he was murdered by the Eagle Monster in Episode 33 while attempting to save a child from Egos. This fatal encounter occurred because he had left the Big Baser without his Battle Cossack uniform.