If you look at the other images in the series, you'll see that the note probably means the 12th time she masturbated this week, not the 12th time she was walked in on.
October 9, 2012, 11:51 PM
Masturbating with an electric toothbrushPanicking because her mother burst in while she was halfway through
12th time this week (71st time in total)● ● ● School, Year 2, Class C
● ● NanamiOctober 9, 2012, 4:12 PM
In the train on the way home from school
