Classification and ideal proportions

The ideal ratio of the length of the miniskirt, the exposed portion of thigh, and the over-knee part of the socks is often considered to be 4:1:2.5, with a tolerance of 25%.

Zettai ryōiki fans classify it by visible bare skin area, that depends on height of the socks and length of the skirt. A zettai ryōiki is graded from grade E (too much leg is seen, the skirt is also too long) to grade A (short skirt, high socks, short exposed area).

Popularity

The clothing combination is very popular in Japan. As with loose socks, a special "socks glue" can be used to glue the socks to the legs for a perfect look.

Japanese advertising agency WIT launched a campaign in 2013 which paid women to wear temporary tattoos on their upper thighs promoting various products and media. They were encouraged to wear skirts and long socks to highlight the area.

On February 8, 2014 a specialty shop called "Zettai Ryōiki" dedicated to overknee socks and tights opened in Akihabara, Tokyo.

In an episode of the anime "Nana Maru San Batsu", a series about participants in quiz shows, Mari was running through practice questions with Shiki, and asked "The area between the hem of a miniskirt and the tops of a knee-high is called by what name," with the answer of "zettai ryoiki" followed by an explanation.

Etymology

The term originates from the 1995 anime series "Neon Genesis Evangelion", where it was used with a different meaning. In an insert leaflet that came with VHS cassettes, the expression was used as a translation of the English-language term from the anime into Japanese. An A.T. Field was a type of a protective energy shield, dubbed a and made a being using it impervious to attacks. Also, the term could refer to . The "Neon Genesis Evangelion" manga also gave a shortened version of the term, "Zettai Ryōiki", in furigana next to the words "A.T. Field". The idea of a "holy area no one can intrude upon" was where the current meaning of the term originated. The expression first spread in the otaku community and then started to be widely used outside of the otaku subculture. For example, it is now included in the general-purpose dictionary "Daijisen".

Trademark application

On February 13, 2006, the Japanese company Banpresto, which produced video games based on "Neon Genesis Evangelion", filed two applications for registration of the term "Zettai Ryōiki" as a trade mark. Both applications were rejected on June 26 on the basis of unpaid registration fees.