Shōkai
Shōkai was a Buddhist monk of the Ji-shū school, disciple and close relative of Ippen, the first patriarch of Ji shū. He was also considered the founder of the Rokujō-ha branch of the school.
After Ippen's death in 1289, he founded the Kankikō-ji temple in 1291, and most importantly wrote the text of the Illustrated Biography of the [Itinerant Monk Ippen]. This is the oldest biography of the patriarch known today, so it has a very strong historiographical value.