Itihasa

Ancient Japan, 12,000 years ago. At that time, people were still close to gods. One day, Takano, a village boy who believed in invisible gods, picked up an abandoned child. He named the child Tojiko and raised her as his little sister. Seven years later, Takano and his family's village is attacked by an invisible and evil god, Ijin. Takano, Tojiko, and Aohiko, who is like an elder brother to Takano and his friends, are saved by the followers of the visible god, Yagami, and the three of them join forces to confront Ijin. A science fiction epic depicting the battle between gods, deities, and their followers.

(Source: Shueisha, translated)