The Golden Darkness is Watching

(from ebookjapan):

A young girl, Esther, is brought by car to live in a town called Windrow for her brother Samuel's medical treatment.

In Windrow, Esther sees a lot of cats, and she learns the reason for the increase in the number of cats due to the circumstances of the residents.

Soon after, a big trouble breaks out between the residents and the many cats, which become ferocious because of their hunger, and Esther and the others get involved....