Ningai (951 - June 22, 1046) was a Shingon Sect Buddhist monk who lived during the mid-Heian period. His father was Korehira MIYAMICHI. He was born in Izumi Province. He is also known as Ono Sojo, Ame Sojo and Ukai Sojo. He is the founder of the Ono School of the Shingon Sect.
Ningai entered the Buddhist priesthood under Gashin of Mt. Koya before being ordained by Gango of Ishiyama-dera Temple. He went on to establish Mandara-ji Temple (which later became Zuishin-in Temple) in Ono, Yamashina in the year 991 where he founded the Ono School. In 1018, he mastered rainmaking prayers and was promoted to the rank of Gon-Risshi after performing a miracle. After nine successful rainmaking prayers, his reputation spread to Northern Song Dynasty China. During this time, he was made Todai-ji Betto (administrator Todai-ji Temple) and To-ji Choja Homu (Director of temple affairs and chief abbot of To-ji Temple), and promoted to the rank of sojo (highest rank of the Buddhist priesthood). In his last years, he was granted Teguruma no senji (special permission from the emperor to enter the imperial palace in a hand cart).
He compiled 'Penitence in Taizokai' - a text that is recited by all schools of the Shingon Sect.