Minitruck
This is a Mitsubishi Minitruck. There are several makes and models of minitruck in Japan, which makes them very noticeable. The Mitsubishi minitruck is the most famous. Even if you haven’t seen one, there are several varieties of petite utility vehicles here that use the same chassis. Americans might laugh at them because of their dimensions compared to a Ford Pickup, but they are extremely capable and sturdy little trucks with a surprising area of flatbed space.
Or not.