Unusual Incident in Seireitei?! Gotei 13 Invading Army Arc!

A month after Aizen's defeat, daily life has settled enough for Hitsugaya to grumble about Rangiku slacking on the cleanup around the transported Karakura Town. In the living world, Rangiku and Nanao finish setting the last barriers and step into the Dangai for the return trip, but their Hell Butterflies suddenly dissolve into energy. Back at the Kurosaki Clinic, Ichigo and Rukia leave their bodies to handle a Hollow and notice a Senkaimon opening nearby with someone emerging from it. Kon, left in Ichigo's body, later follows that lingering Reiatsu and discovers an unknown girl lying wrapped in cloth.

At the Research Institute, Hitsugaya reports that Nanao and Rangiku never checked in after saying they were returning. Kagerōza Inaba confirms there is no record of the pair passing through the Dangai. When the two lieutenants finally reappear, they insist only three hours have passed since their last message, though far longer elapsed in Soul Society. Mayuri determines a time gap has opened between the worlds and is expanding, warning that Soul Society will soon be unable to reach the living world at all.

Yamamoto places Mayuri in charge of investigating the Dangai, with Kenpachi providing security and Byakuya, Renji, and Hitsugaya assisting. During the survey, Mayuri reports the anomaly is man-made just before Nemu detects something approaching and a blinding light erupts from the wall, cutting off all contact and stranding the study group. Byakuya's team returns having found an important object near the rendezvous but no trace of Mayuri's party. At the Urahara Shop, Kisuke reveals Yoruichi vanished in Soul Society three days earlier and warns Ichigo against overexerting his unstable powers, which will fade faster if pushed.

Summoned by a suspicious order, Ichigo and Rukia flee through the Dangai as the Kōtotsu pursues them; Ichigo drops his Substitute Badge into the cleaner and activates Bankai to escape. Arriving weakened in Soul Society, he is confronted by Hitsugaya and other Shinigami who move to detain him as a witness, insisting it is nothing personal. Meanwhile, in a room full of mannequins, Inaba greets copies of Nanao and Izuru, the first hint of the Reigai duplicates driving the arc. The closing Shinigami Illustrated Picture Book recaps Kon's origins as a discarded Mod-Soul from Project Spearhead. This installment is anime-original with no manga source and no formal fights.