First of all, yes, all houses have a large step up at the entryway that makes a good place to remove shoes and leave them before stepping into the house. In my own home I might just sit down on this big step to tie my shoes, but when out visiting I politely balance on one foot or the other while trying to put my shoes on. (No buckles on shoes in Japan though sports shoes have to be tied.) A very bad habit that parents try to break children of (and which I am very guilty) is the smashing of the shoe heels just because it is too much trouble to get the foot completely inside the shoe!
Families with older people living with them will often have a bench or chair just inside the door so that someone can easily sit down to slip shoes on or off. Entryways are often so small though that this convenience isn't common. Tetsu's mother is considered handicapped since she was injured during the war and she walks with a prounounced limp and with a cane but still she wrestles with her shoes whenever she goes out. She considers herself very ungainly since she has to stoop over every time she puts on her shoes and so she dislikes going to places where shoes have to be removed. I remember one Japanese restaurant we took her to where shoes were supposed to be taken off but the waitress, realizing my mother-in-law's difficulty waved her in, shoes and all (but we weren't walking on tatami mats. I don't think that would have been allowed!)
Tetsu works at a convalescent home and so there are a lot of people going in and out that are in wheelchairs or have trouble with taking shoes on and off but according to him, the custom is the custom, and everyone takes their shoes off. If someone should ask to go inside wearing shoes because of a physical disability, then probably any institution or home would make an exception (so see, anyone wanting to visit Japan who needs special shoes need not be overly concerned!) but the person would be offered a rag so that the soles could be wiped before entering.
Going barefoot outside in summer is not an activity that Japanese children have experienced. One just does not bring outside dirt into a home no matter what. Even dogs who live in the house and go for a daily walk are used to the custom of stopping at the front door after the walk and having their feet wiped before they enter the living area.
Yesterday Choco spent the morning outside and when I went to bring her in in the evening I was met with a muddy dog! The snow is melting around her doghouse and she was wading around in the mud! Unfortunately Choco does not like to get her feet wiped and ususally I'm not too fastidious but yesterday I picked her up (heavy dog!) and deposited her in the tubroom to give her feet a rinse before she was allowed back in the living room. Maybe I should have given her a complete bath!