The 4th story from Yuri Tengoku Anthology. "Bound By A Red String" is another all-girls' boarding school story, in which romance blooms between two roommates.
この空の向こう; プリンセス学園; 彼女と私と赤い本; Autumn Sleepiness; Beyond This Sky; Bound by a Red String; Friends (Anthology); I'm Here; My Partner; Omoi no Kisetsu; Oshida J-O; Princess Academy; Rooftop; She - I - and the Red Book; Shining Mars; The Glade in the Forest