Prequel to Lupin the IIIrd the Movie: Fujimi no Ketsuzoku.

An airport bombing terror attack occurs in the frigid Roviet Union.
The unexpected suspect is Lupin III.
However, the "other Lupin" cornered by Zenigata claims his innocence.
Zenigata, a man of justice, finds himself confronted by the mysterious "fake Lupin."
A national conspiracy, the truth behind the bombing, and the intersection of two Lupins -- Zenigata's beliefs are put to the test.

The most rugged, passionate and melancholy buddy action movie in the series' history begins!

(Source: Official Website, translated)

Watch LUPIN THE IIIRD: Zenigata to Futari no Lupin Online