Yoshida Mitsuyoshi (吉田 光由, 1598 – January 8, 1672), also known as Yoshida Kōyū, was a Japanese mathematician in the Edo period. His popular and widely disseminated published work made him the most well known writer about mathematics in his lifetime.He was a student of Kambei Mori (also known as Mōri Shigeyoshi). Along with Imamura Chishō and Takahara Kisshu, Yoshida became known to his contemporaries as one of "the Three Arithmeticians."Yoshida was the author of the oldest extant Japanese mathematical text. The 1627 work was named Jinkōki. The work dealt with the subject of soroban arithmetic, including square and cube root operations. Source: Wikipedia (en)