During the first episode, we see Akira running down the street without pants. Then he asks a bystander, and the guy just lends his pants to Akira. Is this related to some cultural reference, or is it never explained and is a strange plot element even to Westerners?
It's never explained but I imagine that Akira transferred him some large amount of money from his phone. The man is clearly elated at whatever Akira offered him.