Class S (culture)

Class S (Japanese: クラスS, Hepburn: kurasu esu), also known as esu kankei (エス関係; lit. "S relationship") and abbreviated as S or esu (エス)^[a] is a social practice that emerged in early 20th century Japan most commonly expressed as a relationship between a younger and older student at an all-girls school.^[1][3][4]

Notes

1. In this usage, "S" can be used as an abbreviation alternately meaning "sister", "shōjo" ('girl'), or "sex".^[1][2]