She does have the Shiba look, now that I think about it. Especially after the timeskip, she looks a lot like Kukaku. How would that happen though? Unless Isshin was juggling Masaki with some other lady for a while, lol. Or maybe he's just not the first Shiba to have spent time in the WotL. It's interesting that Orihime and Chad have had their powers developed and explained, yet Tatsuki's been in the background for so long.
---------- Post added at 05:47 PM ---------- Previous post was at 05:44 PM ----------
Tatsuki being a Shiba would make a whole lot of sense too, considering their past and her now powers, and Kubo's old drawing of Tatsuki in shinigami robes with a katana and fox hide around her neck.
This is an interesting take on it, who is to assume that no other Shiba isn't in the human world hiding?
You guys are honestly overanalysing the scene. Take a look at this page again where Aizen explains the whole reiatsu sensing matter:
Before he explains he has a flashback and in it we see Tatsuki along with Aizen's pre-butterfly form. Then Aizen explains the whole reiatsu sensing matter. He says by achieving his evolution both human and shinigami would be unable to even feel his reiatsu unless he voluntarily lowers it down. He even makes an anology with how a two dimensional being would be unable to interefere with a three dimensional one.
He's obviously refering to how he lowered his reiatsu when he was chasing Tatsuki. We usually don't see reiatsu so obviously we were unable to tell when he lowered his reiatsu and when not. As for when his reiatsu got back up, it was probably some time during his battle with Ichigo but it doesn't matter because we usually don't get to see reiatsu. Reiatsu is like air. It's there but you aren't usually aware of it.
Honestly I don't know why so many people doubt what Aizen said in Deicide. Sure it was confusing but if you read it dozens of times you'll realise it makes sense. Deicide is the mini-arc written with the most comlex style anyway.