As you exit the station area through the ticket gates, take note of the direction you are facing — east. The warehouse is directly east of the station. To get there, you’ll basically be walking in a long straight line on a street adjacent to overhead train tracks.
The wide street you are about to cross is Showa-dori.
Directly in front of you (and under the train tracks) is a Chinese-style soba shop, with a large picture of a bowl of noodles on its sign. There’s a narrow one-way street on either side of the soba shop. Take the street on the LEFT.
You’ll cross a few small streets, then you will come to a large one at a set of traffic lights. In total, you’ll walk about 500 meters/yards, so it shouldn’t take longer than five or ten minutes.
The entrance is just before the corner. You should be able to see a sign with our orange rice man logo.