Hoom...sorry for the necropost, but this series seemed really interesting to me. After several searches, I turned up some very interesting information. It appears that going to a lesson in your underwear is part of an end-of-12th-grade celebration very common in Norway. It's called "Naken Russ" and there's some information about it here:
h-t-t-p://bjornsmestad.blogspot.com/2005/05/russen.html
All the links on that blog post are dead, but I'm sure that someone searching "Naken Russ" can find eventually find another source for these pics, or at least some similar ones. I'm not going to pursue it now, maybe later. Hope someone finds this helpful.
