Grandmother must travel to Nagasaki and, reluctantly, leaves Mimiko at home alone. To Mimiko's delight, she is not alone after all when a father (Papanda-San) and son (Kopanda) set of panda bears move in. Cheerful Mimiko has a very strange family for a little girl - a Panda for her Papa, and his son, Panny, calls her Mom! Unaware they are zoo escapees, Mimiko adopts Papa Panda and little Panny and writes to grandmother, "I've got myself a daddy and a baby". Rapid-fire adventures begin for the trio, yet Mimiko keeps her cool whether dealing with Panny's mischief, zookeepers' threats, or a close call with a raging waterfall.