The Yin Yang Twins Yuna and Nayu!
Nayu is the Yin Cat
Yuna is the Yang Dog
They like to sing, play games and draw art.
For eons the yin and yang were represented by dragons, but 10,000 years ago they started to intermingle with other species. To the point that there are black rabbits and white foxes, always the opposite specie will be born. For they can only be born as set of twins each time.