The corridor of the Fifth Division Barracks was quiet.
Footsteps echoed through the corridor, Hirako Shinji's feet striking the wooden floorboards loudly.
Yan Si's footsteps were softer, like a cat's.
The two stopped outside the lieutenant's room. A little light spilled from beneath the door.
Hirako raised his hand and knocked.
Knock. Knock.
About three seconds later, the rustle of fabric came from inside, and then the door slid open.
Aizen Sōsuke stood behind it.
He wore a light-colored kimono for lounging, with a haori draped loosely over it, unfastened.
His hair was a little more disheveled than usual, a few strands hanging over his forehead.
His eyes widened slightly behind his glasses when he saw Hirako, then curved into a gentle smile.
"Captain Hirako," Aizen said, his voice carrying a hint of sleepy languor. "What brings you here so late?"
Then his gaze moved past Hirako to Yan Si, who stood behind him.
His smile deepened a little.
"It's been quite some time, Brother Yan Si."
His tone was natural, like that of an old friend reunited.
Yan Si nodded. "Brother Aizen."
At those words, Hirako Shinji's eyes flew wide open.
There was no mistake. Their forms of address had changed.
When they last met in the alley, Aizen had greeted him as Fifth Seat Yan Si, and Yan Si had answered, "Mm."
Now it was Brother Yan Si and Brother Aizen.
Hirako's fingers curled slightly at his side.
But this was not enough. A mere change in how they addressed each other was no evidence.
Aizen was highly regarded in the Gotei 13 and had a good reputation throughout the Seireitei.
Gentle, diligent, responsible, and unfailingly courteous to everyone.
Without solid evidence, Hirako could not act.
Before Aizen could say anything else, Hirako reached out and grabbed his