Enter! The World of the Shinigami

Racing through the collapsing Dangai, Ichigo Kurosaki and his friends flee the melting walls as a tendril of the Kōryū snags Uryū Ishida's cape, forcing Yasutora Sado to tear it free. When the Kōtotsu, the cleaner that sweeps the passage every seven days, bursts into view, Orihime Inoue turns and blocks it with Santen Kesshun, the resulting explosion hurling everyone safely out into the Rukongai. Yoruichi Shihōin scolds her recklessness, warning that touching the Shun Shun Rikka itself would have killed her, but the group has entered Soul Society unharmed.

As Ichigo rushes toward the refined Seireitei, massive Sekkiseki slabs crash down to seal the city behind an enormous gate, and the giant Jidanbō Ikkanzaka reveals himself as its guardian. He separates Ichigo from the others with a rock barricade and insists on a one-on-one duel. Ichigo blocks Jidanbō's first strike one-handed, then withstands the repeated blows of Juppon Jidanda Matsuri and the final Banzai Jidanda Matsuri, shattering both of the giant's axes with a single swing of Zangetsu.

Defeated and weeping over his broken axes, Jidanbō is moved when Ichigo apologizes for breaking them, and he concedes total defeat as both warrior and man. He grants the group passage, praising Ichigo's heart, and strains to heave the colossal gate open. Yet he freezes partway up as Captain Gin Ichimaru approaches, leaving a frightened Jidanbō to name him as Ichigo looks on.

Yoruichi introduces the Rukongai as the poorest yet freest region of Soul Society, ringing the Seireitei where the Shinigami live, and explains that no one has forced the White Way Gate in the 300 years of Jidanbō's watch. Ichigo recounts that he reclaimed his Shinigami powers in only five of his ten allotted days, spending the rest sparring Kisuke Urahara, which built the stamina and nerve that let him overpower the giant. Sado privately grasps that Urahara gave Ichigo the combat experience he had lacked.

The duel with Jidanbō is settled decisively, opening the gate for the invaders, but the celebration is cut short by Gin's arrival, halting the giant mid-lift and setting up the next confrontation.

Episode 21 is part of the Soul Society: The Sneak Entry arc and adapts chapters 71 through 74. It aired in Japan on March 1, 2005, and in English on February 3, 2007, opening with *~Asterisk~ and ending on Thank You!. The anime added the group's screaming flight from the Kōtotsu impact and Yoruichi remarking on Jidanbō's shattered axes, while trimming lines such as Yoruichi noting the giant could fell thirty Hollows in one swing. Several beats were also reordered from the manga.