Do you capitalize ninjas in, 'Release the Ninjas!'?

Ninja definition, (often initial capital letter) a member of a feudal Japanese society of mercenary agents, highly trained in martial arts and stealth (ninjutsu) who were hired for covert purposes ranging from espionage to sabotage ... He was gonna join the fight, you know, really he was, got his ninja getup fitted and everything. read more

Nor do you capitalize druids, gladiators, plumbers, or any other professional class, except at the beginning of a sentence. In English, words are capitalized at the start of a sentence, or if they are proper nouns, or, occasionally with poetic licence, for a specific type of emphasis that mimics use as a proper noun. read more

Cleaning Ninjas is a locally-owned family business serving Lincoln and Omaha, Nebraska. The mission of Cleaning Ninjas is dedication to the highest quality of client service delivered with a sense of warmth, friendliness, individual pride, and awesomeness. read more

I mean there cool and all, but most ninjas just killed the innocent there not like the best fighters in the world everybody just stereotypes asians and martial arts for ninjas if I do a CHINESE kung fu move people will say" you got ninja skills" but not all martial arts is ninjas. read more