I went to government school in Australia for 12 years. I can honestly say I have never witnessed a student wearing a tie, long sleeved shirt with shorts (or acubra).
In fact, I have never seen any student wear a tie. Or (since 1986) a long sleeve shirt.
http://www.ajf.australia.or.jp/english/studyaus/primary/eakit/index.html
Why is my government lying to the Japanese?? See that picture at the bottom of the page of Japanese students? Yeah, that's more like what we wore -- what they're holding? Not so much.
(For the record, boys wore shorts and girls wore skirts / shorts. Both wore polo tops (plus jumper / tracksuit in Winter). In high school jeans replaced tracksuit bottoms.)
