Bleach, Volume 8 (Bleach #62-70)

Ichigo knows that to retrieve Rukia from the Soul Society, he'll have to enter that world himself. But his fight with Rukia's brother Byakuya showed, in no uncertain terms, that Ichigo still has a great deal of rigorous study and training ahead of him. Deep beneath Kisuke's Urahara Shoten, Ichigo practices his fighting and hones his spiritual energies, and now he must face the most daunting challenge of all: prevent his Chain of Fate from consuming itself, or be forever transformed into a soul-devouring Hollow!