The Forbidden Research... Nozomi's Hidden Secret!
Ichigo awakens at Urahara's shop, mystified as to how he was rescued. Urahara tells him that there are several ways to escape the restrictive current but none to escape the cleaner so it is unknown how Ichigo escaped. Elsewhere, Mayuri uses his zanpakuto to drug Inaba. Inaba then summons fake Isane and attacks her. At Urahara shop, Rukia then explains Project Spearhead to the rest of the group in which mod souls were used. Inaba then takes the soul candy from the Reigai and swallows it, resulting with Inaba being rejected from his body and the Reigai taking the effects of the drug. Inaba then ressurects most of the defeated Reigai, unleashing their true strength and revealing his backstory as the one who created mod souls. The episode ends with Nozomi admitting she was the first mod soul.
Aired 05/07/2011EP 329 - The Forbidden Research... Nozomi's Hidden Secret!

Bleach
Ichigo Kurosaki is a rather normal high school student apart from the fact he has the ability to see ghosts. This ability never impacted his life in a major way until the day he encounters the Shinigami Kuchiki Rukia, who saves him and his family's lives from a Hollow, a corrupt spirit that devours human souls.
Wounded during the fight against the Hollow, Rukia chooses the only option available to defeat the monster and passes her Shinigami powers to Ichigo. Now forced to act as a substitute until Rukia recovers, Ichigo hunts down the Hollows that plague his town.