Sanetsuna Kuroda ranks among Shinogara's top six elite ninja operatives. He relentlessly pursues protagonist Hayate after Hayate assassinates his own father, Shinogara's leader. During this hunt, Sanetsuna critically wounds Hayate with near-fatal injuries, directly compelling Hayate to transfer his soul into his sister Shiori's body for survival. Sanetsuna maintains an unwavering antagonistic role, dedicated to capturing Hayate for betraying Shinogara's secret dominion over Japan.