The Final Getsuga Tenshō!? Ichigo's Training!

Isshin explains that the Dangai stacks layers of compressed time, so a single year outside equals two thousand within, and he anchors forked blades into its walls to hold back the crushing Koryu for roughly two thousand hours. He urges Ichigo to use that window to learn the true nature of the Final Getsuga Tensho from his Zanpakuto through Jinzen. Above ground in Karakura Town, Keigo panics to find everyone asleep, is repeatedly punched by Tatsuki, and the two carry unconscious classmates toward the school while sensing the town has been relocated.

Meditating at last, Ichigo sinks into an inner world now flooded with water and is pulled under by a hooded young man who turns out to be Tensa Zangetsu, appearing this way because Ichigo has entered while in Bankai. The spirit attacks and flatly refuses to teach the technique, declaring that what he wishes to protect and what Ichigo wishes to protect are not the same. Isshin, sensing the struggle, warns that Zanpakuto never surrender their secrets willingly.

Outside town, Aizen and Gin cross into Karakura, and a waking bystander disintegrates simply from standing near Aizen's pressure. Spotting Tatsuki, Aizen recognizes Ichigo's friends from Ulquiorra's report and decides to kill them to force Ichigo's new power to completion. Tatsuki orders Keigo to flee. Back in the flooded inner world, Tensa Zangetsu thrusts his hand into Ichigo's chest to drag out the source of his despair, which proves to be Ichigo's inner Hollow, grinning behind a horned mask.

Isshin details the Dangai's time density and holds back the Koryu so Ichigo can train. Ichigo performs Jinzen and meets Tensa Zangetsu, who refuses to teach the Final Getsuga Tensho. Aizen and Gin enter Karakura Town and target Ichigo's friends, forcing Keigo to run. Tensa Zangetsu extracts Ichigo's despair, revealing his inner Hollow.

The episode adapts chapters 408 through 410 within the later Fake Karakura Town fighting and stages no full battle. Its Illustrated Picture Book gag shows the inner Hollow complaining about the waterlogged inner world while Tensa Zangetsu contentedly swims among the fish.