Reference to the three wise monkeys, sometimes called the three mystic apes, who are a pictorial maxim. Together they embody the proverbial principle "see no evil, hear no evil, speak no evil". The three monkeys are Mizaru, covering his eyes, who sees no evil ; Kikazaru, covering his ears, who hears no evil ; and Iwazaru, covering his mouth, who speaks no evil.

There are various meanings ascribed to the monkeys and the proverb including associations with being of good mind, speech and action. In the Western world the phrase is often used to refer to those who deal with impropriety by turning a blind eye.