Chosonninja's source of the uriginal sanada ten braves history was from a stupid movie.
Reviews on the video are here.
i misunderstood one of review.
"When Oda Nobunag chopped a man's head..."
"A man's head flies like a rocket much faster than when Oda Nobunaga chopped a head in NHK Taikoki drama."
Anyway, it meant the rocket head was funny.