Yasuo and Yukiko were named after Yasuo Yamada and Yukiko Nikaidô, the voice actors for Lupin and Fujiko in the first Lupin III TV series, Lupin the Third (1971).
The first Lupin III anime to sponsor and use the McDonald's restaurant name.
This OAV was specially made for the 40th anniversary of the Lupin III franchise.
The old man who gives Yasuo the jacket and gun is implied, by the knowing smile he gives when he's told he did a "good job", to be the original Lupin, who has retired and is guiding his successors from the shadows.