"Ayanami" refers to a character named Rei Ayanami from the famous Japanese anime and manga series, Neon Genesis Evangelion. This tag indicates that the porn video features either cosplay or fantasy content involving this character. It may also be used to indicate that the video has an overall theme related to the series, such as mecha or science fiction elements. Note that this specific reference is not in English but rather refers to a well-known anime character.