Kedama no Gonjirou  

けだまのゴンじろー, Gonjiro The Furball

On one occasion, a shy fifth-grade pupil named Makoto Maegami stumbles upon a peculiar jumping hairball that latches onto his head! After consuming one of Makoto's buttons, it morphs into an extraterrestrial-like character known as Gonjiro. Equipped with the power to morph into any form to aid in any predicament that Makoto may encounter, Gonjiro becomes Makoto's protector in any tricky circumstances. Consequently, Makoto's escapades become intertwined with Gonjiro's assistance in any "hairy" predicaments.