Legend of Crystania: Hajimari no Boukensha-tachi

When Redon, prince of the kingdom of Da’nan, witnesses his father and mother die during an attack orchestrated by the usurper Malid, he and his friends Kwairde, Nasare and Aderishia, escape and use a crevice in the Gods’ Wall to climb over the once insurmountable wall into Crystania, the land of the gods. There, Redon hopes to acquire the strength he needs to free Da’nan from Malid, but the crevice in the wall is healed and Redon and the others are forced to stay in Crystania. The group learns that Crystania is ruled by the animal gods and is inhabited by human tribes, who each follow their own animal god. The land isn't what Redon expected it to be, and he soon finds himself vexed in the lands affairs.