Jones

Jones is a Rex Devon cat, who appears to be very intelligent, but not very social with other cats. He was initially a unnamed cat who likes to read books in the cat infested mall, which seems unusual for a cat.
He also likes to walk around the mall as a routine, until that one faithful day where a group of the human trio went to search for the missing family here. Where the cat took notice of it and decide to help them out, even directing them to the 2 Son of the family, Masaki and Len. Who are hiding somewhere in storage room.
He is brought home by the trio, where the Grandma agreed to keep him and gave him the name, Jones

Jones are implied to be a former human, as he pawed one of the poster in order to communicate with the trio to answer their question about him. Where he also answered "I am" when they questioned if he is infected.

The cat has a tongue sticking out as a resting face, green fur, a striped fur pattern and a slender body with large ears. Which gave him a nickname "Alien cat". His green fur may have been a pun with that nickname, as aliens usually also depicted as green colored humanoid.

This cat is a reference to the cat in the franchise "Aliens", who is named Jonesy. Which explains his breed being Rex Devon due of the nickname "alien cat" and his name being Jones.