Well not to speak in generalizations...but yea, you totally can. Literally EVERYONE does. That's a generalization but you see them everywhere. While most are mamacharis...I've seen expensive bikes and ebikes as well just parked against a rail outside of a convenience store or a restaurant. This is by far the best place I've ever lived with regards to honest people and safety. I lost my wallet in Tokyo a few weeks back, and went to the nearest police station about an hour later...it was already there, with all the YEN and USD still there. Love this place. But I still won't be leaving a $$$ bicycle outside...it just "feels" wrong. At a cafe or something while I grab a bite...sure.