It's penis size. According to the latest, most comprehensive study to date using 500,000 males, the average length of a Japanese male's.
From 10 to18 cm: The penis size in a country comparison. Are you Average penis size by country: worldwide comparison Japan, 10.92, 171, 6.39 %.
Respondents had to guess the length of the average erect penis and also answer what an ideal penis is, length-wise. No matter what people.