After reading the whole case (I was away for a few weeks and missed the whole action) I'm left with 3 questions....
1. Who is this strange woman whose traces are found in Shinichi's house? Maybe Vermouth......
2. In pg 11 of ch 812, I thought Okiya was hiding a comb, why does he have to hide a comb!?Also, when they revealed Okiya's neck in Ch 812, it was only the front part, so my guess is that whatever he's hiding in either in the side or back part.
3. What is with Sera's 'Bad Kid' statement? As for that, I doubt that Sera is in LOVE with Shinichi or something. Rather I think it has something to do with her and Akai (Assuming Akai's her brother. I posted my theory on it in the Sera identity speculation thread. Though it might seem ridiculous right now, I just posted it.
As for Okiya knowing Conan's identity, I think he knew that conan was shinichi but just didn't understand how he was faking it so well... he might have doawn up a conclusion that it was all thanks to the bow-tie, but nothing can be more convincing that seeing it happen in front of his own eyes. And Conan surely suspects Okiya after this.... Too many mistakes Conan-kun!
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