An Apron is a cover worn during cooking and cleaning to avoid the clothes underneath getting messy. The "Hadaka Apron" (Naked Apron) is popular in Japan.
Aprons are cloths that are designed to protect the wearer from the normal splattering and stain normally associated with cooking. They are also at times worn for other household chores, such as cleaning. While they come in a variety of designs and colors. The most popular seen in manga and anime is the basic white. Ones design for women often are decorated with frills.
A style of smock apron is frequently worn by students in home studies classes to teach cooking. These designs have sleeves and tie at the neck and back, similar to a regular apron.
The apron is an essential part of the maid clothes that are worn by maids, but is always white.
Cosplay Fetish
Strike Witches wearing nothing but aprons
Normally aprons are worn while cooking to avoid getting any mess on clothes, in Japan however a fairly popular fetish known as the " Naked Apron" involves a person wearing either just underwear or absolutely nothing under her apron.
The association is derived from a sexualization of the domestic ideal. Seen as the "sexy housewife" out to seduce her husband.