Also known as "Return of Lupin III."
This episode is a direct sequel to the first series pilot and includes flashback footage from said episode. Tadaaki Yamazaki wrote both stories, and Takiguchi Jumpei played Mister X in both episodes as well.
The idea of a reunion was based on the Shin Lupin III manga chapter Lupin Family Lineup.
This episode ranked #8 in the Lupin III Best Selection rerun of favorite episodes, as chosen by Japanese fans.