Fight to the Death! Ichigo vs. Ichigo

Running low on the fuel that keeps her Gigai working, Rukia slips off at dawn to restock at the Urahara Shop, buying replacement supplies along with a special item she has ordered. Ururu, however, mistakenly pulls the order from a box marked as defective merchandise. Later at school, Rukia drags Ichigo aside and gives him a duck-topped canister of Gikongan, an artificial soul meant to force his own soul out so a substitute can occupy his body while he fights Hollows. When Ichigo swallows a pill to see how it works, his soul is ejected and a placeholder personality takes over his shell, one that bears no resemblance to him.

The substitute soon reveals it is no ordinary placeholder. It smashes a fence with a single kick, leaps to rooftops in astonishing bounds, and vaults up to Ichigo's classroom window, where it flirts with Orihime and provokes Tatsuki into hurling desks. When Ichigo and Rukia return, the intruder brutally beats Ichigo before fleeing, and Rukia recognizes it as a Modified Soul, a member of the discontinued Project Spearhead that once placed combat-built souls into corpses. All such experiments were slated for destruction, yet this one survived.

Rukia explains that Soul Society law demands these souls be eliminated to protect the living. As Ichigo chases the escapee across town, the Mod-Soul revels in his newfound freedom until he stumbles on three boys casually deleting the creatures they raised in a handheld game. Enraged by their careless cruelty, he moves to attack them, and Ichigo intercepts his strike at the very last instant.

Rukia buys a defective Gikongan dispenser containing a runaway Modified Soul. Ichigo swallows the pill and is separated from his body, which the Mod-Soul then takes over and uses to cause chaos at Karakura High School. Rukia identifies the escapee as a product of the cancelled Project Spearhead and explains the law requiring Mod-Souls be destroyed. Ichigo blocks the Mod-Soul's attack on three children, setting up their confrontation.

The episode adapts chapters 13 through 15 within the Agent of the Shinigami arc, and marks the first appearance of the character later named Kon. It aired in Japan on November 9, 2004, and in English on October 14, 2006. The adaptation trims many small gags while expanding the Mod-Soul's rampage and Ichigo's beating; a closing preview has Sado fall silent instead of introducing the next episode.