Lupin is given a job to return 6 treasures to their original areas for an old friend of his, so Lupin can receive an even better treasure to gain.

Mark Williams, an old master thief, that Lupin teamed up in the past. After Mark past away, he left a dying wish for Lupin. In order to obtain the Trick Diamond, Lupin must return 6 of Mark's stolen valuables to their original spots. Only then will Lupin be able to learn the location of the Trick Diamond.—J LeGault