Following a lead from Fujiko, Lupin and Jigen excavate the sea floor in Kiritappu to search for a lost underwater treasure that supposedly holds the secrets of time travel. After the Lupin gang escapes a run-in with the law, a strange man calling himself Kyousuke Mamoh strands the Lupin gang hundreds of years in the past. Now Lupin, his friends, and his relentless rival Inspector Zenigata must quickly navigate two feuding tribes and solve the mystery of the lost treasure. Otherwise, the time-hopping villain Mamoh will erase Fujiko from existence by wiping out her ancestor!

(Source: Discotek Media)

This movie is a remake of episode 13 in the original Lupin III series.