3
Deckard did not speak any Japanese of Mandarin throughout the first Blade Runner movie. However, everyone seemed to be able to communicate with him. In one of the scenes, he went to a food stall to buy food. Although the vendor spoke Japanese and he spoke English, Deckard seemed to have no problem understanding his Japanese. On the other hand, the vendor seemed to be having trouble understanding what Deckard was saying, and eventually Deckard gave up arguing and sat down.