[1] A renowned Japanese calligrapher, Yamamoto was a Rinzai Zen Buddhist priest who followed in the footsteps of the famous Master Hakuin Ekaku.

According to the book Zen and the Art of Calligraphy, Yamamoto is sometimes called the "twentieth century Hakuin.

By today's standards Gempō would be deemed legally blind, and it was not until later in life that he was able to write and read.

Yamamoto is probably most remembered for his many zenga paintings, which can be found hanging at Ryūtaku-ji today.

[3][4] In 1934, he testified in favor of his disciple Nissho Inoue, a militant Nichirenist preacher, during the trial for the League of Blood assassinations.