Why don't Japanese girls wear long pants?

Of course, Japanese girls should go barefoot in winter, not only to look good, but also because their mothers educate them in this way for health and postpartum problems in the future. This kind of leg health can only be passed on to their mothers, not to their fathers. So Japanese girls don't wear long pants in winter. Therefore, I have come up with a possibly unreliable explanation, why women in China are confined after giving birth, and why they can't play in the World Cup.