The Soul Society—expansive, eternal, and fundamentally alien. In the strictest terms, this realm existed separate from the World of the Living. Through the Senkaimon, the world-crossing gate guarded by Jigokuchō, Aoki stepped into the plane long ruled by the Shinigami: a land divided between the Seireitei and the sprawling, often overlooked Rukongai.
From his first step onto the spiritual soil, Aoki was struck not by awe, but by discomfort. Around him bustled countless souls—residents of the Rukongai. They ran errands, quarreled, laughed, and lived what passed for lives after death. But to Aoki, something felt deeply wrong. These weren't reincarnated people finding peace. They were shadows, echoes of their former selves. The afterlife was no paradise. If anything, it was harsher than the mortal world.
In Seireitei, the central stronghold, the Shinigami governed with authority rooted in centuries of doctrine. The Four Great Noble Houses—Kuchiki, Shihōin, Tsunayashiro, and Shiba—stood at the top of a rigid social hierarchy. This aristocratic rule, coupled with the Gotei 13's militaristic order, reinforced a cruel reality: peace was reserved for the privileged. This was not a world Aoki cared to belong to. It was precisely this rigid system that repulsed him—and one of the reasons he had no desire to become a Shinigami.
Yet Kisuke Urahara's request loomed in his thoughts, pulling him into a reluctant engagement with this world's machinery. If he was to find a path back to his own reality, he might have to bend.
The Shin'ō Academy, or Shinōreijutsuin—the Spiritual Arts Academy—had been established by none other than Yamamoto Genryūsai Shigekuni roughly two thousand years ago. It served as the training ground for prospective Shinigami, offering mastery over Zanjutsu, Hakuda, Hōhō, and Kidō. From its gates emerged the vast majority of the Gotei 13's current captains and lieutenants.
But Aoki had no interest in a student's path. With his strength and intelligence, infiltrating the Gotei 13 directly was a faster option—and entirely possible with the right attention.
One month later, inside the First Division's barracks, the great bell tolled across the Seireitei, summoning the captains of all thirteen divisions. In the main hall stood Yamamoto Genryūsai Shigekuni, his very presence dominating the room with the weight of centuries.
"We begin," the old captain said, voice heavy as stone. "Report your findings."
Captain Mayuri Kurotsuchi of the Twelfth Division stepped forward, his golden eyes gleaming with curiosity and annoyance. "No traces. None. The spiritual pressure that erupted in the Living World—absolutely unprecedented. Not even a residual particle of reiryoku left behind. But let me be clear—it was of a level that exceeds even the average Captain."
Kurotsuchi was a monster in his own right—a scientific genius and a madman. For him to admit ignorance was rare.
Byakuya Kuchiki, Captain of the Sixth Division and scion of one of the Four Great Houses, spoke next, calm and restrained as ever. "Rukia Kuchiki vanished at the exact time and place of the incident. There were no signs of a struggle."
Kurotsuchi sneered. "Let's be honest, Kuchiki-taichō. Under that level of spiritual pressure, her survival chances are nil. Even if it wasn't a direct attack, the residual force alone could have vaporized her."
He was wrong, of course. Rukia wasn't dead. But Aoki, in his moment of awakening, had left behind traces of Hollow-like spiritual pressure, confusing even the most seasoned experts.
"Continue surveillance," Yamamoto ordered. "An unknown Hollow of such magnitude cannot be allowed to exist. And one more thing—reports from the Rukongai suggest the emergence of a figure of immense power. Kyoraku Shunsui, you will investigate. If deemed viable, recruit him into the Gotei 13."
The meeting adjourned. As the captains dispersed, Kyoraku Shunsui, captain of the Eighth Division, turned to his old friend, Ukitake Jūshirō.
"You coming with me?" he asked, adjusting his straw hat lazily. "I swear, the old man sends me to do every thankless job."
Ukitake chuckled softly, his ever-pale complexion shadowed by illness. "You know how it is. He trusts your instinct. And this one… this so-called 'monster'… might really be something special."
**
In the Rukongai's 78th district, Zaraki—one of the most lawless sectors—Aoki watched a group of children playing tag, their laughter echoing off the shattered walls and crooked roofs. Despite the desolation, the kids loved him. In just four weeks, he had become a local legend—a gentle giant with an iron will and a mysterious strength.
But he knew better than anyone how fragile their peace was.
"ROOOAAAR!"
A Hollow tore through the fabric of space with a garganta, descending upon the district like a predator. Even in Soul Society, weaker Hollows could occasionally infiltrate the outer Rukongai districts, drawn by the dense concentration of souls and spiritual energy.
Panic exploded. People scattered. The Hollow—an Adjuchas-class based on its power—locked eyes on the very children behind Aoki.
Thud. Thud. Each step of the beast thundered through the cracked earth.
The children ran to Aoki instinctively, and his smile faded.
One motion. That was all it took.
Aoki extended his finger and touched the Hollow's mask.
The Hollow disintegrated instantly—no cry, no struggle. Its spiritual signature was eradicated at the molecular level.
From a nearby rooftop, Kyoraku Shunsui whistled low. "Well, well. He didn't even use a Zanpakutō. He's not even registered in the Academy's system… and yet…"
Ukitake narrowed his eyes. "He destroyed an Adjuchas-class Hollow without effort. That level of control… he's not ordinary."
As they descended, Aoki pretended not to notice. When Shunsui began clapping, his casual demeanor made the children laugh again.
"A marvelous display," Shunsui said with a grin. "Name's Kyoraku Shunsui, Captain of the Eighth Division. This is Ukitake Jūshirō, Captain of the Thirteenth. Care to join us for tea—or perhaps the Gotei 13?"
They spoke for hours. By the end of the day, Aoki was extended a formal invitation to join the Shinigami ranks.
What shocked them both, however, was Aoki's choice.
"I'll join," Aoki said, "but place me in the Fourth Division."
The Fourth—headed by Captain Unohana Retsu—was the medical and support division. Known for healing, not fighting.
Neither Shunsui nor Ukitake could hide their surprise. A warrior of Aoki's caliber, joining the support corps?
But Aoki had his reasons. He needed time. He needed information. And above all, he needed to stay close to Soul Society's spiritual and medical archives—where secrets of time, space, and reincarnation were stored.
The monster chose the path of healing. And the Soul Society had no idea what it had just welcomed through its gates.