According to the Heike Monogatari, in the Heian period, Raigō, on the basis of a promise with Emperor Shirakawa of receiving as much reward as desired if it had effect, continuously prayed for the birth of the emperor's crown prince, and in 1074 (in the Jōhō years) on December 16, it was finally succeeded. As a reward, Raigō requested for the construction of an ordination platform (kaidan) building for Mii-dera, but opposition forces from Enryaku-ji at Mount Hiei obstructed this and prevented it from being granted.