Ikenie no Otsutome wa,

"Did you go for a walk...with somebody else?" Once every 10 years in Hikaru's dying town, a sacrifice is offered to the Dog God in exchange for the town's protection and prosperity. As the only young person left in the increasingly depopulated town, Hikaru decides to give himself to the Dog God as a sacrifice. There's only one catch: the Dog God is a tyrannical pervert who lives in a luxury high-rise apartment building in Tokyo!

(Source: Ichijinsha, translated)