Kokoro is a plump and polymorphous cat who does not lack energy or ideas to entertain her pals and in particular Keito, her best friend, a lazy ball of yarn who lets herself be drawn into a new activity every day.

In each episode, Kokoro and Keito go out to play and explore the surroundings, a magical world made up of fairy and comfortable settings, straight out of sweet dreams. A fabulous playground, suitable for a thousand and one activities that Kokoro always initiates with enthusiasm. At the end of the day, after the effort, the two friends can finally relax and fall asleep, much to Keito's delight!