I call BS. A lot of small residential streets in Japan don't even have sidewalks, and people just walk in the street as you should:
Sometimes they have sidewalk-ish areas, but they're not physically separate from the road, just painted differently. Again, people just walk in the street, and as a result cars go slowly. Pedestrians make an effort to get out of the way of cars when there are cars on the street to be polite and not inconvenience the driver, and cars drive slowly and carefully because their drivers acknowledge the street as a shared space.
Now, if the OP meant a two-lane road with crosswalks, a yellow dividing line, street lights, etc. Then that would be different. I could imagine someone objecting to walking across that kind of road without using a crosswalk, even if it was empty. Those aren't shared spaces, those are car spaces. It would be keeping with Japanese culture to obey the traffic laws there even if the road was empty.
