If you couldn't tell, these are the two girls on the top left corner (our right) of the group photo - the darker-skinned girl and the Rukia look-alike. The former seems to be referred to as 褐色ちゃん/Kasshoku-chan (Brown-chan) and the latter as 集合写真右上の子/Shuugou shashin migijou no ko (upper-right group photo kid/girl)

Haha, I feel like a bit of a dork for kind of wanting to get into watching K-on simply because of these background characters.

I'm almost wondering if this focus on background characters isn't some sort of subtle viral marketing campaign.

hey, someone drew her neat (dark skin girl)