Neo_X said: Doesnt most of them have them leave behind their clothes?
You said it yourself, "Most". There are other ones that came before Naruto that also left logs or other objects(like those little monk statues) in the ninja's place. Ninja Cadets did it(1996) and especially more comedy anime/manga's did it. Even for ones that weren't centered around ninja's at all. It is for the most part rather "Un-realistic" so mostly more serious stories with ninja's do the more realistic thing such as just leaving clothes.