There's a saying in Japanese that goes "senaka de kataru" (背中で語る, literally: talk with one's back). It's used to indicate masculinity, as a man who doesn't need to talk is seen as persuasive, powerful and cool. A real man doesn't give explanations using his mouth. He just stands in silence and lets his back talk for him.
Today we collected a series of illustrations tagged "otoko no senaka" (a man's back)!