Senbonzakura (Zanpakutō spirit)

Senbonzakura manifests as a tall, fair-skinned man with blue eyes and long dark-brown hair, worn in a lengthy ponytail bound by a white ribbon with two bangs falling to his chest. An ornate mask conceals his face, fitted with golden teeth, fanged black lips, gold projections at the sides, and a triple cherry-blossom crest at the brow. He dresses in a pale purple kimono striped in white and sashed with trailing loops of white cloth, red-and-gold pauldrons linked by a banded chain, and red gauntlets and greaves.

In combat Senbonzakura stays composed and calculating, though he freely mocks his opponents and cannot abide being humiliated, losing his cool the instant it happens. He can be curt to the point of rudeness, appearing without warning and leaving without answering. His early hostility toward Byakuya, including a cruel loyalty test that demanded he defeat Sode no Shirayuki, later proves to be an act: in truth he is deeply loyal and deferential, having been freed from Muramasa's control long before, and he holds firmly that a Shinigami and blade reach their full strength only in harmony. Away from the fight a more childish, hypocritical side shows, quick to shift blame, short on patience, easily enraged by others' mistakes, and prone to drink. He is courteous enough to call Sode no Shirayuki 'Lady,' never removes his mask even while bathing, and carries a spare in case it breaks. Shunsui Kyoraku and Jushiro Ukitake remark that his temper closely echoes Byakuya's younger self.

Senbonzakura enters the story among the other rebel Zanpakuto spirits, clashing with Byakuya and appearing to fall before his master defeats him and restores his senses. Playing along with Muramasa's uprising, he demands that Byakuya prove himself by cutting down Rukia's spirit Sode no Shirayuki, then trades blows with Zabimaru's halves Saru and Hebi and battles Ichigo Kurosaki to repeated draws, slipping away each time. He unleashes his Shikai with the command Scatter, scattering his sword into a thousand petal-like blades, while his Bankai, Senbonzakura Kageyoshi, multiplies them into a crushing cloud driven by techniques such as the collapsing sphere Gokei and the sword-ringed Senkei. After trailing Muramasa to Karakura Town, he finally reveals to Ichigo and Rukia that Byakuya had broken Muramasa's hold on him long ago and only feigned betrayal; he then fights at Byakuya's side against Koga Kuchiki, serving as his master's eyes when illusions blind him, and helps seal the Garganta before returning to the blade. During the later Toju crisis he joins the hunt for rogue spirits, becomes trapped inside the research institute with Saru and Hebi and wreaks havoc trying to escape, and lends his strength to bring down the final fiend Kirikaze before his materialized form fades for good.