Some fans think that, given the later time frame, the protagonist is the original Arsene Lupin's son and the father of Lupin the Third, although it's more to do with the fact that this series is set in an entirely different universe.
Grognard is based on Lupin's partner from the 1971 live action series.
Unusual for societal standards, Kelly has her coat wrapped from left to right like a man's, instead of from right to left.