When Ritsu annoyed Mio (instead of doing her homework)... I was positive we'd see little demonic figures in the text (ref Ichigo M.).
edit (who's on first): never gets old... though I've seen them do it with more energy in other instances.
Also... I was unaware Ritsu had a little sister.... and Ritsu reminds me a bit of a girl in my son's high school who just seemed to live for drumming.
Interesting tshirt Mio has on during the flashback (a skull?? Mio??
)