Yosano was born in Kyoto as the son of Buddhist priest, and was a graduate of Keio University.

After graduation, he taught Japanese language for four years at Tokuyama Girls' School, in what is now Shunan city, Yamaguchi prefecture.

On 11 May 1894, he published a strongly worded article encouraging the reform of traditional Japanese poetry, or waka, to give it more originality and thus make it more popular.

[2] In 1900, Yosano founded the literary magazine Myōjō (Bright Star), and soon collected a circle of famous poets, including Kitahara Hakushū, Yoshii Isamu and Ishikawa Takuboku.

The magazine was immediately popular with young poets who shared Yosano's enthusiasm for revitalizing waka through the medium of tanka poetry.