Originally Posted by
evergrn
Can't answer a lot of these questions unfortunately... But as far as Health-Sports Day (Taiiku no hi) goes, I don't know that you're really going to come up with anything in terms of any exciting event you can participate in. To me, it's just a day off and the significance to a visitor would be to plan things accordingly (ie, certain attractions may be a lot more crowded than a typical Monday).
Ah, it's also worth mentioning that certain attractions like museums that are usually closed on Mondays will be open that day, and will instead be closed on Tuesday.