Draft:Saimon (liturgy)

Content taken from Dragon King
As already mentioned, Esoteric Buddhists in Japan who initially learned their trade from Tang dynasty China engaged in rainmaking ritual prayers invoking dragon kings, under system known as or shōugyō [no] hō, established in the Shingon sect founded by priest Kūkai who learned Buddhism in Tang China. It was first performed by Kūkai in the year 824 at Shinsen'en according to legend, but the first occasion probably took place historically in the year 875, then a second time in 891. The rain ritual came to be performed regularly.

The shōugyōhō ritual used two mandalas that featured dragon kings. The Great Mandala which was hung up was of a design that centered around Sakyamuni Buddha, surrounded by the, the ten thousand dragon kings, Bodhisattvas (based on the Dayunlun qingyu jing 大雲輪請雨經, "Scripture of [Summoning] Great Clouds and Petitioning for Rain"). The other one was a "spread-out mandala”(shiki mandara 敷曼荼羅) laid flat out on its back, and depicted five dragon kings, which were one-, three-, five-, seven-, and nine-headed (based on the Collected Dhāraṇī Sūtras).

Also, there was the "Five Dragons Festival/ritual" (Goryūsai. 五龍祭) was performed by onmyōji or yin-yang masters. The oldest mention of this in literature is from Fusō Ryakuki, entry of Engi 2/902AD, 17th day of the 6th moon. Sometimes the performance of the rain ritual by Esoteric Buddhists (shōugyōhō) would be followed in succession by the Five Dragons Ritual from the The Five Dragon rites performed by the onmyōji or yin yang masters had its heyday around the 10–11th centuries. There are mokkan or inscribed wooden tablets used in these rites that have been unearthed (e.g., from 8–10th century site, and a 9th-century site.

In Japan there also developed a legend that the primordial being Banko (Pangu of Chinese myth) sired the Five Dragon Kings, who were invoked in the ritual texts or read in Shinto or Onmyōdō rites, but the five beings later began to be seen less as monsters and more as wise princes.