Story related but to give a bit more detail than the other solution you need to go to the docks obviously , try to get there early in the day.
talk to the guy passed security on the left in the hard hat he'll direct you to warehouse 18, talk to the lady inside at her desk. She'll say she has no work and to try warehouse 12. I'm not sure if you need to go inside or not and talk to the guy there but at around noon outside you'll bump into Goro who'll agree to help you, meet him at noon the next day. Warehouse one is right of warehouse 12 refer to the map below.
If he doesn't appear just run around and come back.
Once you meet Goro and Mai at noon the next day you need to head to the Alpha Trading Office at 2pm there is no need to wait you can head right on over and the achievement will pop once you go inside.