Koshiba Hiroshi (小柴 博, November 9, 1884 - June 19, 1925) was one of the founders of the Japanese Scouting movement. He was born in Tsuwano-chō in Shimane Prefecture.
He graduated from Tsuwano Elementary School. He entered Himeji Junior High School, a state school run by Hyogo Prefecture, but dropped out due to family reasons.
In 1903, he became a student at Shimane Normal School.
In 1905, he received a full Elementary School Teacher's licence, and became a teacher at Tsuwano Elementary School.
In 1907, he went to Tokyo, and worked at Akasaka Jinjo High School. Together with his colleagues, Hasunuma Monzō (蓮沼門三) and Iso Kikuma (磯規矩馬), he participated in the Shūyōdan (修養団) movement.
In 1909, he started the youth branch of the Shuyodan (修養団幼年会, Shūyōdan Yōnenkai). This group received support from, among others, Kurushima Takehiko (久留島武彦), Kishibe Fukuo (岸辺福雄) and Amano Kijihiko (天野雉彦), and held 61 meetings in six years, before being disbanded. It is reported that meetings consisted of events such as readings of children's stories and inspirational and improving stories, singing, excursions and group training, and were always extremely popular.