As I drew this sketch, I thought about the fact, that this could be a FLIRT-TACTIC of the book: Flirttactic #1: Position yourself at the roadside leaning against a wall without a shirt on and wait for the Ladies who come around … I guess, Kakashi would get them all ^^.
You just can guess what his students would think: Naruto: I still don’t get it what’s so interesting about that book! Sasuke: He better should train us than reading Jirayas trash! Sakura: OMG! Our Sensei looks so sexy! *nosebleed*