March 3rd is traditionally Girl’s Day, or Hinamatsuri. A tradition of setting out dolls since the Heian period, which ended in 1185 and is famous for the spread of Buddhism, the writing of the Tale of Genji, and the increase in power of the Samurai class as the right-hand of the imperials. This was considered an important time for the court, and is usually the set period of historical dramas, featuring ladies in the court with many layers of kimono, the capital was in Heian (now modern day Kyoto), Byodo-in (Phoenix Hall), and House Governments.
The dolls are setup earlier in the year, usually on Setsubun (Which you can find an example of here and a link to the DVD for Haruhi-chan’s dub is here!) and are taken down on March 3rd. These are usually in sets, with the Emperor and Empress at the top and center. The simple setups will only include the two dolls, while the others can be set up in homes anywhere from one platform to seven, including the different members of the Imperial Court, various effects such as fans, and stands for the diamond shaped mochi. You can watch a video of a family setting up a 2 platform version here. Their version is from Kyoto, where the Emperor and Empress are switched, so the setup will change, depending on the region.
For those of you interested in learning Japanese as well, you can find the traditional song with translation here. Or, you can have a throw back to MINIMONI’s Hinamatsuri song here instead!