Sin appears in Sailor Moon: Another Story. She is the Oppositio counterpart of Sailor Moon. She blames Neo-Queen Serenity for letting her parents die during the Black Moon Clan's attack, thus driving her rage. Her only remaining family is Anshar, her younger brother.
She is named after the Babylonian god/godess of the Moon.
Sin looks similar to Usagi/Sailor Moon with the colour of her hair, eyes and outfit colour. Her hair is the same blonde as Usagi's but without odangos and in two long ponytails. They zigzag at the ends and are held in with red ribbons. Her fringe is less round than Usagi's and is more like Queen Nehellenia's fringe. Her eyes and outfit colour are slightly more purple-ish than Sailor Moon's fuku. She wears a full black bodysuit with purple and white patterns on it and her toes have points to them. She wears a large white collar with golden plates (like Galaxia's) protruding from it, she also has an upside down heart and red tie, mirroring Sailor Moon's usual heart brooch and bow. Finally, she wears golden anklets and bracelets, a tiara like Sailor Moon's with a triangle on it and golden earrings with the same triangular shape.
- Hell's Attack - Sin's signature attack. This attack had the appearance of a beam of energy that was fired at all the Sailor Senshi.
- Genkaku - Confused the target for five turns, making them attack enemy and ally alike, and also prevented them from using items or techs.
- Kamaitachi - Inflicted a series of swift, slicing attacks against all opponents.
- Toxic Mist - A numb-based attack. It would inflict damage and sometimes poison the targeted character(s).
- Sonic Wave - Petrified the targeted Senshi, which prevented them from moving, attacking, or defending. The effects lasted until the Senshi was healed with a BathMedic, Pork Chop, or Red Berry.
- Jaaku na Hadou/Hell's Surge - A single blast of energy that hit all of the Sailor Senshi at once and caused a significant amount of damage.
- Sin is the only Oppositio Senshi to not have the Miryou attack.