A newly arrived student in a wheelchair has returned to school after an illness and immediately greets Tsuzuki Ui - who she fondly refers to as "Rei-kun" - with a kiss. Tsuzuki soon comes to realize that she is the daughter of a wealthy family and a former opponent from an internet murder mystery game he participated in. The student has become fixated on Tsuzuki since he was the only one who managed to beat her, and now she wants to play a real-life murder mystery game with him. Unfortunately, her current focus is the supposed suicide of Tsuzuki's father, and she seems to have her suspicions on his little sister Haruka for some unexplained reason.
