Sinon is a talented VRMMO game player in «Gun Gale On-line» and «ALfheim On-line». Her real name is Asada Shino. She is nicknamed Hecate in GGO, after her gun «PGM Ultima Ratio Hecate II», a unprecedented .50 caliber anti-materiel sniper rifle. She is likely one of the major characters of the Phantom Bullet Arc and the primary feminine player that Kirito met in GGO. She plays GGO to conquer her trauma regarding weapons.