Japan is suffering a severe shortage of its legendary ninja warriors.

The nation's booming inbound tourism market has led to the creation of dozens of ninja-themed attractions, theme parks and restaurants across the country, meaning that some are finding it difficult to attract ninja with even the most basic skills.

Those skills include an adeptness with "shuriken" - throwing stars - and swords, as well as training in unarmed combat, acrobatics, concealment and first aid.

"With the number of foreign tourists visiting Japan on the increase, the value of ninja as tourism content has increased", Takatsugu Aoki, manager of the ninja squad for Nagoya-based advertising agency Sankosha Co., told the Asahi newspaper.