Desperate Struggle Under the Moonlit Night, the Mysterious Assassin and Zanpakutō

At Ichigo Kurosaki's school, curious classmates pepper Rurichiyo Kasumiōji with questions, but her attendant Kenryū fields every one with evasive answers and bristles at Ichigo for his blunt manner. Ichigo treats the whole affair as a bother yet senses that Kenryū's excessive caution points to a real threat. That night, both Ichigo and Rukia Kuchiki detect an unnatural Reiatsu next door and spot Kenryū scanning his rooftop moments before an intruder crashes through it in a burst of light. As Enryū spirits Rurichiyo to safety, Kenryū leaves the fight to Ichigo, and the armed assassin proves to wield a peculiar sword.

The weapon's polished hilt catches the moonlight and briefly blinds its target, nearly wounding Ichigo and then striking Rukia. Ichigo works out the trick and turns it against the assassin, angling his own blade to flash the reflected light back and disarm him. When he tries to learn why Rurichiyo is being hunted, the assassin chooses death, letting Ichigo's follow-up strike finish him rather than talk.

With the danger past, Kenryū and Enryū return the still-sleeping girl, and Ichigo gathers everyone so Kenryū can explain. Rukia identifies the Kasumiōji name as belonging to Soul Society's high aristocracy, and Kenryū is astonished to learn she hails from the Kuchiki Clan. He recounts that Rurichiyo is the rightful Kasumiōji heir, orphaned of both parents, and that a steward named Gyōkaku Kumoi has been maneuvering to unseat and kill her, which drove Kenryū to hide her in the Human World. He formally asks Ichigo to guard her, and Rukia commits them both before Ichigo can object, on the condition that Rurichiyo never learn she is a target.

In Soul Society, Kumoi confers with the leader of his agents and dispatches him alongside several assassins to eliminate Ichigo and his companions.

Rurichiyo Kasumiōji and her attendants Kenryū and Enryū pose as transfer students under Ichigo Kurosaki's watch. An assassin wielding a light-reflecting sword attacks, and Ichigo defeats him by turning the moonlight trick back on him, though the killer takes his own life rather than reveal his purpose. Kenryū discloses that Rurichiyo is the Kasumiōji heir threatened by the steward Gyōkaku Kumoi and asks Ichigo to protect her. Rukia accepts on both their behalf, and Kumoi sends more assassins after them.

The episode is an anime-only entry of the Amagai arc, also known as the New Captain Shūsuke Amagai arc, and adapts no manga chapter. It introduces the assassin's special weapon, a Bakkōtō named Saiga, along with the wider Kasumiōji conspiracy. The Shinigami Illustrated Picture Book short shows the Shinigami Men's Association reduced to meeting in a bathroom, where Iba rejects Hisagi's phone design as insufficiently manly and Ōmaeda's as too costly.