Kotaro Sakuma (佐久間 小太郎 Sakuma Kotarō) is a young boy who defied Jark Matter's occupation of Earth with his younger brother, Jiro Sakuma. Inspired by Stinger, Kotaro decide to join the Rebellion. He later gains his own personal Kyutama from Shou Ronbou's predecessor, Big Bear to become Koguma Skyblue (コグマスカイブルー Koguma Sukaiburū, lit. Little Bear Skyblue), the eleventh member of the Kyurangers. His alternate form is called Ooguma Skyblue (オオグマスカイブルー Ooguma Sukaiburū, lit. Great Bear Skyblue), though what this form is is currently unknown as it has yet to be seen.