Money from Heaven

Fracois [sic], a nuisance of a little girl, has fallen for Lupin, even going so far as to place an advance-warning message on his behalf in the newspaper. She wants Lupin to replace the real Oppenheim Rose, a ruby which her father, a jewelry appraiser, switched with a fake. But he's up against the Louvre's maximum security unit.

Synopsis excerpt via Kitsu.