A.9405K
Aiura Kyouko's alias on arcade games, due to the character limit of 8 letters.
※ 9405 is Japanese wordplay on 'Kyouko'; 9(き[ゅう])4(よ[ん])0(お)5(こ)≒きょうこ(橋子)
Sometimes the dot or K, or both could be dropped for even tighter limits; A9405K, A.9405, A9405 etc.