In the series its explained that Zangestu is apart of Ichigo and was surpressing his powers, and didn't want Ichigo to become a shinigami, and practically always hinders Ichigo as one day he might have to kill him based on his changes. Sorry but I read this in a wiki. Zangestu tells Ichigo he should know that the Zanpakto is physical representation of Ichigo's power, Ichigo remembers its ribbon red from his friend. My question is: one episode Toshiro and another guy had same dream for the sword and both wielded short time and soul society decided only one can wield him, if the Zanpakto is apart of a shinigami then how can two people have same power? And how come Toshiro had dreams to wield while in Ichigo's case he didn't. If it wasn't for rukia power awaking and Urahara forcing through kido Ichigo could never became a shinigami. 

Its like Toshiro's Zanpakto was given to him by soul society because they agreed he was worthy after beating the other guy.