Rabbit friends Hup and Hop

In a forest, under a pine tree, lives a little bunny called Hup. He longs to discover the world and find a friend, but he's too scared to set off on an adventure. That is, until a little yellow ball of yarn rolls up to his burrow. Hup believes it's the sun, come to make his dream of a great adventure come true. He musters all his courage and runs after it. What adventures await him? And will he meet the friend he's missing so much along the way?