February 22nd
What to wear - anything black, and if you have a ninja costume go ahead and wear it.
What to eat/drink - going out for Japanese food for lunch or dinner is best. Drinking tea throughout the day is a good idea too. Maybe a little sake or Japanese beer at night would be fun as well.
What to watch - sadly there aren't any real good ninja movies out there but there are plenty of ninja related videos on YouTube to pass the time.
What to listen to - traditional Japanese music
What to read - The Bansenshukai, the Ninpiden, the Shoninki, or any of the many ninja books that are available today.