The importance of "bihaku"
Unlike many of the Western countries, Japanese tend to not show much skin when going out. They favor "bihaku" meaning white, clear skin and therefore cover up as much as possible using clothing, hats and sun umbrellas. Even in the scorching summer, you will see many people wearing long pants, long sleeves, thin gloves, hats, etc. Also, low cuts are not worn as often in Japanese women.
Young people have a slightly different fashion. In the summer, they wear skirts, shorts and summer dresses that show the legs. However, low-cuts are not as common as in the US or Europe.