Zegai-bō (shite in the first act) is a tengu from China. Tengu are mythical beings often portrayed as a long-nosed, winged creatures living in the mountains. They are thought to have great spiritual powers as well as deep knowledge of Buddhism, though they use their skills to trick monks. In China, Zegai-bō has corrupted many proud and arrogant men within the Buddhist community. Next, he wants to challenge Buddhism in Japan, so he disguises himself as a yamabushi priest and visits Tarō-bō (tsure in the first act), the tengu of Mt. Atago, in Western Kyoto. Their target is Mt. Hiei, on the opposite side of the city, headquarter of the Tendai monks. However, all tengu fear the power of Fudō Myōō, fierce guardian deity of Buddhism. Zegai-bō laments that, since the fate of all tengu is to be enemies of Buddhism, they are all destined to be destroyed. Though they realize that their objective is almost impossible to achieve, the tengu decide to fly to Mt. Hiei.
News of Zegai-bō’s plotting has reached the monks of Mt. Hiei, and a Servant of Imuro-no-sōjō), the Head Priest (ai-kyōgen), was ordered to descend from the mountain and perform an exorcism. He is on his way to the city when suddenly a strong wind rises, preventing him to enter the city.
Imuro-no-sōjō (waki) and other monks (waki-tsure) are on their way to the imperial palace to alert the emperor. Suddenly the earth shakes and the sky trembles. Zegai-bō, now in his real form of Tengu King, appears. He threatens Imuro-no-sōjō but the priest responds with an invocation of Fudō Myōō and of the twelve guardian deities of Buddhism, who appear in his defense. The deities of Iwashimizu Hachimangū, Matsuō Taisha, and Kitano Tenmangū also join in the counter-attack against Zegai-bō, who is defeated and leaves Japan, promising to never return.
Mt. Atago, appearing in the first act of the play, is one of the sacred mountains of the yamabushi, mountain priests performing ascetic practices and shamanistic rituals, fusing Buddhism with local cults. Tengu, mythical creatures with deep knowledge of Buddhism, are associated with yamabushi, and are thought to live on mountains such as Mt. Atago.
The story of a tengu from China visiting Japan where he is defeated by a priest can be found in the Heian period collection of tales Konjaku Monogatari. However, the play Zegai is probably based on the visual representations of tengu popularized in the Muromachi period, especially via collections of humorous drawings (oko-e), such as the ‘Zegai-bō illustrations’.
The highlight of the second act is the confrontation between Zegai-bō and the Head Priest Imuro-no-sōjō. At the beginning of the act a stage property representing a cart is brought on stage. The tengu approaches the cart and tries to throw the priest off.