Hi there !
I am hoping someone has pm'd you already to answer some of your questions... Like meeting fellow craftsters & such...
Anyhow - I hope you have already done with all your hotel reservations and fixed your itinerary by now. If you are planning on doing homestay - I hope you have already contacted & made plans with your host family by now.
I hate to be a spoiler
- but you should know that March is a very busy time for Japan - both for the Japanese and the tourists (local & foreign) for many reasons:
1. end of fiscal year
2. graduation from school (uni)
3. moving season - most companies transfer their employees to new posts on April
4. Spring vacation - families go traveling or visiting gramps & grans
5. and like samurii said - it is the cherry blossom season - all over - beginning early March in the southern parts (Osaka & Kyoto) of the mainland proceeding northwards to Tokyo (mid-March) up to further North (around late April)...
6. Conference season - for many scientific associations
Over-all this makes it hard to find good & cheap lodging...
Lots of info can be found on the net -
I hope this helps a bit...
Good luck and have a nice trip to you (and to samurii too...)