On a Thursday afternoon after school, Yumi steps into the second floor of the Rose Mansion as usual, only to witness an unusual sight. Yoshino is staring intently at a point on the table without turning on the lights! What Yoshino is looking at is a box wrapped in department store wrapping paper. The box has 'To my cute little sisters' written on it in the handwriting of Eriko, the former Yellow Rose (Rosa Fetida). Yoshino starts to unwrap the package, but...!? A special story consisting of four chapters begins with a surprise gift!