An Si-eun (安施恩(アンシウン), An Shiun?), known as Siune (シウネー, Shiunē?) in «ALfheim Online» (ALO), is a supporting character in Mother's Rosario. She was the second sub-leader of the «Sleeping Knights», a guild of terminally ill patients who met in Serene Garden and played various virtual reality games as a form of palliative care. An Si-eun had played a variety of virtual reality games, including Insect Site, until the guild eventually arrived to ALfheim Online, where An Si-eun chose to be an undine.