The story centers on a woman who is getting on in years, but all her cats think she's a man so they call her Ojii-chan. One day a brazen cat named Tsushima appears in Ojii-chan's yard.

Web anime of Ore, Tsuhima that is concurrently released during the TV shorts' broadcast, streamed on the Asmik Ace YouTube Channel. 
One day, “Ojiichan(woman)” who likes cats meets a talking(?) cat on the street! 
The name of the brazen cat who was originally a stray cat is “Tsushima.” “Zun,” Ojiichan’s house cat, “Chaa,” who’s spoiled and cowardly, and “Osamu,” a self-centered gangster cat have already been living in Ojiichan’s house, and Tsushima now lives together with them in peace.
Wanna take a look at the wild life of Tsushima and Ojiichan that’s filled with love for cats? 
 
(Source: YouTube video description)

The manga centers on a woman who is getting on in years, but all her cats think she's a man so they call her Ojii-chan. One day a brazen cat named Tsushima appears in Ojii-chan's yard.