Sonansu's capper on the Rocket-dan motto is funnier in Japanese. See, Sonansu is loosely based on this Japanese stand-up comedian who would often utilize the phrase "sonansu" in his act, which roughly translated means "Yes, sir, that's right". Thus, it's sort of like Sonansu is adding the affirmative conclusion to Musashi and Kojirou's motto (sort of the equivalent of "Meowth! That's right!", which in the original Japanese version is "Nya, nyaante na!" or "Nya, what they said!").
It also makes the Sonansu/Sonano conversation scene in "The Mysterious Island of Sonano" doubly funny, because Sonano's name roughly translates into "Is that so?" In Japanese, the whole conversation is just a big back-and-forth of "Is that so?" and "Yes, sir, that's right!"
