Loose socks (Japanese: ルーズソックス, rūzu sokkusu) are a type of sock that is popular among Japanese and Korean girls. They originated from boot socks for mountain climbing, manufactured in and exported from the United States.
In Japan, they were adopted as a fashion that deviated from school uniforms and firmly took root after a long period of popularity.
Foot odor often results from wearing shoes and/or socks, especially shoes or socks with inadequate air ventilation, for many hours. Since human feet are densely covered with sweat glands, excessive perspiration of the feet is the result. This perspiration and warmth provide ideal conditions for bacteria and/or fungi to thrive. The presence of the bacteria and/or fungi does not in and of itself cause odor; instead, as the bacteria consume dead skin cells and moisture, they in turn produce waste material. This waste material is the cause of foot odor. As physical activity increases, foot perspiration, bacterial growth, and bacterial waste production all increase, causing odor to intensify.