what i can share is my mother in law's experience when she went there to visit my brother in law. she's a country girl and doesn't like busy cities or crowds, and gets lost really easily even in her hometown lol. but she said that even though there are soooo many people, even at a busy crosswalk like shibuya, everyone gives you your space. people don't bump into you or brush shoulders with you etc when passing, everyone is very respectful of other people's personal space. she said she didn't feel crowded at all. one of her friends that went with her had a harder time, she's quite heavy and had a hard time getting through the tiny aisles in stores, plus people stared at her because there's not much obesity in Japan, so being a gaijin and heavy she stood out like a sore thumb. she didn't enjoy the trip much but my mother in law loved it and wants to go back