https://en.m.wikipedia.org/wiki/Kūkai
Kūkai (空海; 774 – 835 AD), also known posthumously as Kōbō Daishi (弘法大師, "The Grand Master who Propagated the Dharma") - Japanese Buddhist monk, calligrapher, and poet who founded the Shingon school of Buddhism — the Japanese branch of Vajrayana Buddhism.