User blog comment:Apocaylpse06/Ichigo Kurosaki's (New) Zanpakuto/@comment-1975828-20110815110510/@comment-4173672-20110817063243

InfernoRage is right here, Ichigo's sword from season 1 was his sealed Zanpakuto, Zangetsu came from the release of that big sword he used to carry around. Rukia did transfer her powers to him, but it also awoke his own, in Zangetsu, which was probably already alive from him being half-Shinigami, but we won't know any of that until Tite Kubo releases it