Bleach Season 1 Episode 19

Ichigo trains with Urahara. He is underground trapped in the hole with 72 hours left until his life chain will come to its end. Held by a binding spell, he waits while Jinta and Ururu tease him. When his chain is no more, he goes though the process of becoming a Hollow. In his mind Ichigo finds that he has to find the shinigami box or he will become a Hollow. After he finds the box he comes out of the hole a semi-hollow, semi-shinigami. He breaks the mask and Urahara moves on to the third lesson: defeat Urahara.