Sakiko is a generally polite, refined, and reticent girl on the outside. She's overall very secretive, such as trying to avoid Tomori or Soyo's attempts to contact her after CRYCHIC's disbandment, and also keeps her distance from her classmates (as shown when her classmates did not know Sakiko's first name). She appears to be quite ashamed of her current circumstances and is afraid of anyone learning about them, even getting mad at Mutsumi when she suggested that Sakiko start attending Tsukinomori again.