Born in 1964 in Hiroshima Prefecture. After writing novels for young girls as TSUHARA Yasumi, with his forename written in Hiragana letters, in 1997 he published Yoto using his current name. In 2012, 11 eleven reached first place in the Japanese division of the Second Twitter Literary Prize, while in 2014 Goshiki no fune won first place in the Japanese short story section of All-time Best Science Fiction, a special publication to mark the 700th edition of SF Magazine.