Authentic Records! School of Shinigami

Confined to a cell after Aizen's apparent death, Momo Hinamori dwells on memories of her captain and drifts back to her time at the Shin'ō Academy. In the recollection, she leaves a young Tōshirō Hitsugaya behind in their village to enroll, while Renji Abarai and Rukia Kuchiki rush late to their first day and Izuru Kira prays at his parents' grave. Placed among the top scorers, Hinamori, Izuru, and Renji join the advanced class, and Rukia is assigned to a separate group.

During Kidō drills, Hinamori alone in her group manages to strike a target, Izuru destroys his outright, and Renji's spell detonates in his face. Renji and Izuru later spar and, despite Renji's rougher style, bond over their shared struggles and become friends. A visit from Aizen and his lieutenant Gin Ichimaru leaves Hinamori starstruck, and she gushes about the captain to an unimpressed Hitsugaya back home over watermelon.

Months later, the advanced class travels to the Human World to practice against mechanical dummy Hollows, guided by sixth-year students Shūhei Hisagi, Hotaru Kanisawa, and Aoga. Grouped together, Renji, Izuru, and Hinamori dispatch a training dummy with ease, but a concealed Huge Hollow slaughters the barrier team unseen. It impales Kanisawa, cuts down Aoga, and scars Hisagi across the eye, revealing the ability to hide its Reiatsu and split its talon into blades.

Rather than flee as ordered, Hinamori refuses to abandon Hisagi, and the three students intercept the creature's blades and blast it back with a combined Shakkahō, buying time. When more Huge Hollows converge and the situation turns hopeless, Gin's Shinsō spears through the first, and he and Aizen arrive to annihilate the rest with ease. Aizen praises Hinamori for her courage, cementing her admiration. In the present, she uses Hakufuku to knock out her guard and walks free with grim resolve.

Hinamori, Renji, and Izuru enter the Shin'ō Academy's advanced class, with Rukia in a separate section. Renji and Izuru become friends after sparring. Aizen and Gin visit the academy, awing Hinamori. A field exercise turns fatal when a hidden Huge Hollow kills the barrier team, Kanisawa, and Aoga and wounds Hisagi. Aizen and Gin rescue the survivors, sealing Hinamori's devotion to Aizen. In the present, she escapes her cell using Hakufuku.

This entry adapts Chapter -17 within the Soul Society: The Rescue arc and expands a brief manga flashback into a full episode. Much of the academy material, including the Kidō drills, the sparring match, and Aizen and Gin's visit, is original or heavily enlarged for the anime. Censorship softens the on-screen deaths of Kanisawa and Aoga, and several details differ from the manga, such as the training site being an oil refinery and the students facing dummy Hollows rather than performing Konsō.