Hiyori dies? The Beginning of Tragedy

A Seireitei-wide alarm summons every captain to the First Division as word spreads that the spiritual pressures of Kensei Muguruma and Mashiro Kuna have gone dark. Jolted awake, Kisuke Urahara races to his lab, learns that Hiyori Sarugaki has already set out to assist the Ninth Division, and immediately regrets sending her. Meanwhile Hiyori, grumbling about her lab duties, halts on the road when she senses something wrong.

At the captains' assembly, Genryūsai Shigekuni Yamamoto declares the disappearances an emergency and prepares to dispatch an investigative team. Urahara begs to lead the search himself and is refused, then chastised by Yoruichi Shihōin for his rash disrespect toward Hiyori. Rōjūrō Ōtoribashi, Shinji Hirako, and Love Aikawa are chosen to investigate, with Tessai Tsukabishi, Hachigen Ushōda, and Lisa Yadōmaru added to the group despite reservations about committing the Kidō Corps' top members. Shunsui Kyōraku reassures Urahara that trusting others is part of a captain's duty.

In Rukongai, Hiyori narrowly dodges a looming attacker, and Shinji rushes in to save her, telling her to draw her sword before realizing the assailant is a Hollowfied Kensei. Rose, Love, and Lisa converge, recognizing their friend beneath the Hollow mask and reiatsu. Kensei punches Love and a Hollowfied Mashiro ambushes the group, knocking Rose out and pressing Shinji hard. Hachigen appears and binds Mashiro with Gochūtekkan, then restrains Kensei with Sajō Sabaku, but Kensei breaks the Kidō free. Back at the Twelfth Division, Tessai deduces Urahara intends to slip away and rescue Hiyori, and insists on accompanying him rather than letting him go alone.

Kensei and Mashiro's vanished reiatsu triggers an emergency captains' meeting. Yamamoto assembles an investigative party including Shinji, Rose, Love, Lisa, Tessai, and Hachigen. Yoruichi and Shunsui both rebuke Urahara for his loss of composure over Hiyori. In Rukongai the team discovers Kensei and Mashiro have been Hollowfied, and a desperate battle erupts. Hachigen's binding spells briefly subdue the pair before Kensei breaks loose. Tessai chooses to leave with Urahara so the Twelfth Division captain does not go rescue Hiyori by himself.

This is the two hundred tenth episode, part of the Turn Back the Pendulum arc that dramatizes events roughly a century before the main story. It draws on chapters -103 through -101. The opening theme is Velonica and the ending is Sky Chord ~Otona ni Naru Kimi e~. A lighter closing segment, the Substitute Shinigami Work Diary, has Rukia Kuchiki warning that leaning too heavily on Karakura Town's helpers like Urahara can invite disaster. No formal fights are listed, and the Kidō featured includes Gochūtekkan and Sajō Sabaku.