Mokuren-sonja was one of the ten followers to Oshaka-sama. He has been said to be the best in magical powers. By using his power, he saw his mother suffering in the world of Gaki, a devil in Buddhism. In order to save her, he practiced so many Fuse-gyo(z{s), disciplines of giving, and many merits he made saved her to the Heaven at last. Based on his grand merit, Ura-bon-e is conducted with a purpose of praying for our ancestors.