Shurikenjin is the 39th Sentai Mecha created by AkaRed. Its theme is ninjas, however it received a lot of controversy in that all of the mechs other than AkaNinger's had nothing to do with ninjas. AoNinger's was a (European) dragon, KiNinger's was a dump truck, ShiroNinger's was a dog (This also makes her a furry), and MomoNinger's was a maglev (A type of train). Shurikenjin is the 3rd Ninja-themed mecha after Senpuujin (The 26th one) and Muteki Shogun (The 18th one), however those two had ninja-themed mechas for all of the rangers as opposed to just Red's.
Shurikenjin is piloted by the Ninningers.