Author Replies:
Akaitofu, the pairing for this fic will eventually be Shinji/Ichigo, so the Vizards will show up. They just won't appear until Rukia arrives.
Telling Isshin would be the safe thing to do. His son has a hollow in his head and has seemingly befriended the thing. You could even argue Kisuke has a duty to tell the boy's father.
He's not going to do that though, not when it would take away such a fascinating specimen.
His former comrades battle their inner hollows constantly and live in fear of losing control. Their greatest fear is the hollow overpowering them and going on to slaughter everyone they love.
But this boy, who's only a child despite his heritage, has managed to befriend the thing. Of course it's possible that the hollow is planning on gaining his trust and then betraying him, but that's unlikely. The hollow is as young as its host, he can't see it coming up with something that duplicitous.
It's absolutely fascinating to see Ichigo interact with the hollow. The thing has never taken control, but the boy does occasionally pause to stare into the distance, brow furrowing in response to comments only he can hear. The hollow gives him an advantage during spars as well, Kisuke noticing immediately how Ichigo's faster than a human should be, how his senses are sharper.
Really, he hasn't been so entertained in decades.
"Do we have to do this?" A young voice interrupts his thoughts.
Kisuke turns to smile at the scowling child in front of him, giving in to the urge to ruffle his bright hair, laughing when Ichigo bats his hand away.
"If you want training," he cheerfully responds, "we have to do tests."
Ichigo gives him an adorable scowl but acquiesces and settles down.
"Now, is there anything you want to tell me? Any problems?"
"We're fine," Ichigo scowls at him.
Kisuke pauses, looking at the boy, who seems entirely unaware of what he just revealed.
"We?" He questions, watching as Ichigo's eyes widen.
"Well-I mean-" Ichigo looks away before speaking again. "There's two of us in here," he says, tapping a finger against his head hesitantly. "Shiro's got his own opinions and his own likes and dislikes, he's not me."
Urahara sips at his tea, staring at Ichigo in poorly concealed fascination.
"Care to explain?"
The kid gets more uncomfortable, bouncing his leg up and down in unease before speaking again.
"Like, Shiro likes dango and I don't? We both like fighting but I want to protect and Shiro just likes fighting to fight? And he has different opinions on people, he doesn't like you because-" Ichigo stops again, face flushing as he looks down.
Oh, this is fascinating.
"Shiro doesn't like me?" Kisuke asks, setting down his tea. "Care to explain why?"
Ichigo chews at his lip, twisting his hands in his lap before speaking.
"You smell like blood and death. You look at us like we're lab animals, not people. You're powerful if the shinigami haven't come after you, and we're still not sure just why you agreed to help us. You're dangerous and we can't predict what you'll do or how we should act."
"I helped because you asked," is his reply, ignoring Ichigo's disbelieving snort. "You two are fascinating, but I wouldn't have done anything if you hadn't asked."
Ichigo stares at him, head tilted as he listens to the voice in his head, before responding.
"We don't believe you."
"That's fine," Kisuke responds with a smile. "You don't have to."