Ninja Day is celebrated on the 22nd of February (which is the same as Cat Day). Similar to Cat Day, the reason that Ninja Day falls on the 22nd of February is due to the sound of the number 2. In Japanese, the number 2 is pronounced as “ni”, which is similar to the “ni” in ninja. Thus, it is just a matter of wordplay that the date was chosen as Ninja Day. It is not an official national holiday, though, unless one is stealthy and equipped with the necessary ninja skills to sneak away from school, college, or the office.
Originally, ninjas were warriors from the Iga province in the era of Sengoku (though some types of ninjas may have existed as early as the 12th century). As the ninjas were generally people from lower classes, they did not have access to proper weapons and armor. Therefore, the tools that were used by ninjas typically have an agricultural background, such as the kunai (苦無) and the sickle. Another area which has a strong historical ninja background is Koka in Shiga Prefecture. Thus, the cities of Iga and Koka typically celebrate the holiday. Banners are put up to remind people of the day of the ninja.
In the city hall of Koka, the workers are dressed as ninjas and they do their everyday work operations such as talking to citizens, answering the phones and dealing with paperwork. However, they also make shuriken out of paper!
Since the 2nd of February 2016, various activities and events have been held in honor of Ninja Day to bring attention to the occasion which is still considered new and not so popular yet. Among the many events that have been organized are free rubber shuriken trials for children at a full-fledged ninja training dojo in Karasuma Kyoto Shijo, Oshino Shinobi photo contest, shuriken tournament, and gifts to dogs that have been transformed into ninja dogs during the period of 2nd of February to 22nd of February.
It is interesting that Japan takes such pride in its Ninja history to the point of celebrating Ninja Day. Ninja Day can certainly attract many tourists. As the celebration is relatively new, there might not be many attractions to tourists yet. Hopefully, there will be many in the future!