Once in a while, you will come across these really battered up houses right in the middle of a modern area. Theres still one of these right by the huge Ultramen in high rise Akasaka.
My guess is that these were built and stood their time since Tokyo was flattened in the last war - owned by some old folk who dont want to sell their land.
Back in London I would see battered up houses all the time - especially because I lived in Hackney. Many were full of drug taking squatters.