Yamato is a black cat that has a purple tie around his neck as a collar.
When Rui ran away from home, he met Yamato when both of them were hiding from the rain. Later on, they were picked up by Kai.
Before met Rui, he was a stray cat that had no home. Yamato loves to be near Rui, he usually curls up next to Rui on the sofa.