There is one cat at the local pet shop that has been waiting a long time for someone to bring him home. He has reached adulthood alone in his cage, avoided by potential owners for petty reasons like not being cute enough or being snotty. His fortune changes one day when an elderly gentleman named Fuyuki Kanda comes into the store and chooses to take him home. As a widower left behind by his grown-up children, Kanda seeks a feline companion to alleviate his solitude.

At times humorous and others heartwarming, Ojisama to Neko follows Kanda and the newly named Fukumaru as they experience the joys of living together and learning about each other.