Satsuki Kondō attends St. Cherine Academy as a classmate of Haruka Minazuki and Aoi Kannazuki. She shares a close friendship with Haruka, regularly challenging her to swimming races after school. As a member of the school's swimming club, Satsuki participates in its activities alongside Haruka. Her personality is distinctly bubbly and energetic. While part of the academy's social circle, Satsuki remains outside the primary conflicts involving the Twin Angels and their adversaries.