Tsuki no Umareru Yoru

As a child, Makoto Akitsu fell at a shrine and was consoled by what he thought was the shrine's deity. Years later, while attending a festival with his cousin Shou, he spots the same figure and follows him to a shrine to express his gratitude. The being, a kitsune spirit, explains that human actions have led to environmental destruction and the decline of shrines, causing him to lose his power due to waning belief. By the time Makoto enters high school, he and Shou have inherited abilities from their family lineage, allowing them to interact with and combat demons and ayakashi.