Tite Kubo's hit manga series Bleach inspired a popular anime of the same name, and this juggernaut fantasy action story was soon recognized as one of shonen's "big three." However, despite its many action scenes and remarkable powers, very few Bleach heroes or "good guys" ever perish in the storyline. It's usually the villains who die instead.
In any work of fiction, the heroes are much more likely to survive and succeed than the villains, but even then, Bleach's story seems highly reluctant to kill off any heroes during its story arcs. In the Soul Society arc, for example, absolutely no one died, unless viewers count the slaughter of Central 46 off-screen. Still, Bleach needs some stakes and emotional impact, so once in a while, the heroes really do die.
Yachiru/Retsu Unohana Died Fighting Kenpachi
For centuries, Captain Retsu Unohana was known as a soft-spoken but strong-willed Soul Reaper who had a motherly air about her, and she could intimidate any troublemaker with a glance. That's how Ichigo knew her too, but in the Thousand-Year Blood War arc, Captain Unohana's true nature emerged. She had once been Yachiru Unohana, the first Kenpachi and first Captain of squad 11. She had found and recruited a young Kenpachi Zaraki, and now, the time had come for their final duel.
Only one of them could survive, and Yachiru pushed Kenpachi to the limit to help him realize his true power. She gladly gave her life so her protege could unlock his shikai, Nozarashi, and become who he was meant to be. It paid off, but Kenpachi cried out in despair, unwilling to lose his old mentor and role model in the process. Yachiru found that rather amusing as she died.
Captain Jushiro Ukitake Repaid The Soul King With His Life
As a boy in the Rukongai district, Jushiro Ukitake nearly died of an illness until the right hand of the lofty Soul King, known as Mimihagi, intervened. Mimihagi saved Jushiro's life, allowing him to grow up and train as one of the first-generation Soul Reapers under Yamamoto. He easily survived most of Bleach's story arcs even when facing foes such as Coyote Starrk, but when the Quincy king Yhwach threatened the Soul King, Ukitake took drastic steps to save the Soul King.
Ukitake willingly gave back the life he had been given. At great cost, he helped slow down Yhwach's plans, giving Ichigo and the others another chance to save the world. Squad 13 was left without a Captain, so once the war was over, Rukia Kuchiki replaced Ukitake as Captain, and she still holds that rank as of the recent Bleach one-shot chapter.
Masaki Kurosaki Died When Grand Fisher Attacked
Masaki was born a Quincy, and her life was saved when Captain Isshin Shiba fought off the deadly artificial Hollo called White and gave Masaki his powers to contain the Hollow spirit inside her. Masaki survived to marry Isshin and have three children with him, and her combat days were over. Then, one fateful afternoon, Yhwach activated the Auswahlen and absorbed Masaki's Quincy energy without killing her. This left her vulnerable to attack, and sure enough, a Hollow named Grand Fisher attacked and killed her.
The tragic loss of Ichigo's mother was shown early in the story, but the full details weren't revealed to Ichigo and the viewers until partway through the Thousand-Year Blood War arc, when Isshin explained all this to Ichigo. It made the fight against Yhwach that much more personal.
Captain Yamamoto Died Fighting Yhwach Once Again
For centuries, it seemed that Captain-General Yamamoto was invincible, but he lost his life early in the TYBW story arc, and that had a profound impact on the Soul Society. One thousand years ago, Yamamoto had chosen to not kill a younger Yhwach, and that mistake came back to haunt him. First, Yamamoto's Lieutenant Sasakibe was killed. Then, Yamamoto died fighting his old Quincy nemesis, and Yhwach humiliated him before obliterating his body with arrows.
Yamamoto's death prompted Shunsui Kyoraku, a veteran Soul Reaper, to take his place as Squad 1's commander, and the Soul Reapers would have to find a way to defeat the Wandenreich without Yamamoto's formidable power and expertise. His death made the power of the Wandenreich that much clearer, and the stakes became higher than ever before.
Notably, Yamamoto ended up in Hell along with Unohana, since they both had such dense and powerful spirit energy, and their presence in Hell is what allowed Hell's doors to open from the inside in the new one-shot. Even in death, Yamamoto is still shaping the world around him in big ways.