Ponta, the beloved pet of the Koizumi family, is a sprightly Labrador retriever pup who loves to cause trouble. However, when Grandpa Koizumi invents the Guru Guru Bone, Ponta's inquisitiveness lands her in a spot of bother. After gnawing on the bone, the unsuspecting pup transforms into a human girl!
Despite her astonishment, Ponta heads out of the house and crosses paths with Mirai Iwaki, the most popular boy in school. Mirai comes to her rescue when a car nearly hits her, and Ponta reverts to her puppy form. But her brief encounter as a human has left a lasting impression, and she now finds herself enamoured with Mirai. Using the Guru Guru Bone's power, Ponta toggles between her two forms. But the question remains: can she win Mirai's heart?
