Osomatsu-kun (1988)

"You're seeing way more than double! Try sextuple!"

The adventures of Iyami, a con artist who's always looking for a quick buck, and Chibita, his short-statured kid partner-in-crime, as they make trouble for their town and constantly cause friction with the Matsuno sextuplets, a clan of rowdy identical 10-year-old brothers led by the eldest, Osomatsu.