Watch Saint Beast: Ikusen no Hiru to Yoru-hen OVA Online

The seal which was imprisoning the fallen angels, Kirin no Yuda and Houou no Ruka, is broken and the two decide to get revenge on the God who had cast them to Hell by getting rid of the Heavens that had once been their home. Soon the guardian angels on Earth begin disappearing, and no one in Heaven can explain the happenings. But there is a sense of a vengeful animal spirit at work, and so the four Saint Beasts are called upon to investigate. The 4 Gods of Beasts attempt to rescue the guardian angels, as well as to find out what this evil animal spirit is... (Source: Wikipedia)

A long time ago, Zeus, the great god, created a three–tier hierarchy of angels, top, middle and lower, although they were supposed to be equal. Also, Zeus appointed 6 angels as Saint Beasts who govern the animals of Earth. They were: Go, the seiyu; Shin, the genbu; Rei, the suzaku; Guy, the byakko; Yuda, the kirin; and Ruka, the hooh. However, Kira, the shooting star, and Maya, the fuga, didn’t attend the selection tests and left for the Earth. The six angels fulfilled their tasks faithfully. However, because of Zeus’s increasingly tyrannical acts, they begin to mistrust him. (Source: AnimeNfo)

Long ago there was a war in Heaven which resulted in Judas and Luca – two of the six specially-chosen, talented and strong Saint Beasts – being cast out and imprisoned in Hell for leading the rebellion. But before that Heaven had been a peaceful place where the angels happily lived their lives. In this time, Judas, Luca, Goh, Shin, Rey and Gai are adolescent angels in Heaven who, on the day of Benediction, are made into adults by the supreme god Zeus. With each of the six having their own special abilities and new adult bodies to get used to, opportunities to meet each other arise and new friendships are formed.