Genshin (942-1027) is one of famous Buddhist monks in Japan.
He had studied, beginning at 9 year-old, Buddhism at Mount Hiei on the edge of Kyoto. (The mountain was destined to be the greatest Buddhist center in Japan.)
He became a high-ranked monk Souzu; counterpart of bishop in Christianity. He was an advocator of Amidism (Pure Land Buddhism) and completed religious tract " Ohjoh-yohshuh" (Essentials of Salvation or Essentials of Pure Land Rebirth) in 985. This book was a bestseller describing in graphic terms the horrors of hell and joys of Amida's Pure Land and contributed to the spread of Amidism among the aristocracy.
The legend described in the previous page may be only a legend. However, the legend might have been, intentionally or unintentionally, based upon his Amidism.
citation and reference:
Richard Mason, John Caiger. "A History of Japan", Tuttle Publishing (Originally published by Cassell Australia)