Taiji Yamaga was born in 1892 to a printing family in Kyoto.
Yamaga moved to Tokyo, where he studied Esperanto with historian and Esperantist Katsumu Kuroita.
At age sixteen, Yamaga served as the secretary of Kuroita's Japan Esperanto Society.
At Osugi's request, Yamaga visited Chinese anarchist Liu Shifu and his comrades in Shanghai.
In 1962, Yamaga began writing an illustrated memoirs entitled The Twilight Journal.