No dice on the IMDB. However, I might have found something on Google...
Check this quick! Is
Ninja The Wonder Boy the character you're looking for?
http://page.auctions.shopping.yahoo.com/uk/auction/55175184?aucview=0x10There was also a comedic anime series featuring a kid in a black ninja outfit; very simple animation with completely round,
Doraemon-type eyes on the characters. Unfortunately, I don't know the title and can't find it online...