Sabitsuki is the main character of .flow, who is controlled by the player. Much like the protagonists of Yume Nikki and Yume 2kki, she spends the game wandering around her mental landscape and collecting a multitude of effects. Similarly, not much is explained about her past, or about the things she sees in her dreams.
- Sabitsuki's name continues the tradition of giving fangame characters a name ending in -tsuki. However, the kanji in Sabitsuki's name have a different meaning than the ones in Madotsuki's name. Sabitsuki means "covered in rust".
- According to her equipment screen, the skirt she wears is her favorite one and the clothes she wears are her usual clothes.