According to a survey which Tokyo Metropolitan Government Bureau of Social Welfare and Public Health conducted in 2011-2012, 85% of dogs are kept indoors in Tokyo.
Figure 1: Place Where Dogs Are Kept (Number of sample is 298.)
I was surprised that so many dogs are kept indoors. 40 years ago, most of dogs were kept outdoors in Japan.
It is recommended to keep dogs on leash outdoors. But some owners walk their dogs without leashes.
Figure 2: Do you leash dogs while walking?
Source is Tokyo Metropolitan Government Bureau of Social Welfare and Public Health. www.fukushihoken.metro.tokyo.jp/kankyo/aigo/horeishiryou/siryou.files/23tyousa_gaiyou.pdf