I could see her getting irritated at being interrupted, sure, but I'm just saying that glaring sort of clashed with her being indifferent. It's a big day, though, so I guess her concentration could have slipped.
As for having my character pegged wrong, it's hard for me to tell. Yakumo clearly hates Sachiko with a passion, so he's certainly going to see her in an incredibly negative light. This sort of makes it tough to sift between what you, as a player, believe about my character and what Yakumo, as a character who hates Sachiko, thinks about her.
For example, "It infuriated her even further than no matter how little he studied he was still always in the top ten percent of the class." Putting aside that being in the top 10% of the class without trying is Mary Sueish and just being in the top 10% probably is contrary to the setup that put all our characters in this group, this statement is not true. As I said in the character thread, Sachiko quickly became disdainful of school and learned how to pass with minimum effort so she could devote more time to learning things that interested her.
But I could certainly see why Yakumo would think that was true. Sachiko spent a lot of time in the library, and how would Yakumo know that was on independent research and not schoolwork? Also, people like to have qualities that infuriate people they hate.
Another example: "Scowling in irritation at her need to have everything labeled sorted and thoroughly identified he spoke up before she was allowed to permanently damage them all with a stream of incomprehensible babble." I actually like the first part. I hadn't thought about it, but that's a good, slightly annoying character trait I could really see Sachiko having. (The need to classify.) Thanks for that!
But the babble thing? I doubt Sachiko really does that on a regular basis. But she certainly could have talked enthusiastically and highly technically in, say, a kido theory class she shared with Yakumo, and since Yakumo doesn't like Kido, he forms the opinion that she babbles incomprehensibly and all smarty pantsy.
I hope that makes sense.