Cistern finds everyone of the modern world vulgar and unrefined. She even goes as far as calling Sailor Venus a monkey.
Cistern has light skin and dark hair tied up in a traditional Japanese hairstyle. She wears a dark top with long sleeves that hide her hands and a short floral skirt. Her hair is adorned with a heart and what look like wings and she has large lips.
Cistern emerges from a well near T.A Academy after Minako opens it while looking for a volleyball, granting her freedom. She proceeds to possess Rei (who was searching for Minako) and kiss a classmate saying they are 'unrefined'. She harasses more students until Minako transforms into Sailor Venus. Cistern properly introduces herself and possesses Rei again only leading to Sailor Venus killing Cistern with a prayer slip.
Powers and Abilities
Cistern is capable of possession, though she is seen only possessing Rei. She attempts to 'devour' the students of T.A Academy by kissing them but never succeeds.
- Cistern is a play on words of 'Sister' and that she came out of a well.