Fourteen-year-old Ishii Yui wanted to die. She had tried many times, but now for the first time, she wants to live. To survive a death game where 333 people with the surname "Ishii" were gathered in a white room. If they failed, they would instantly explode, and only one person can make it out alive. Meanwhile, detectives Fushimi and Hachisuka receive a missing person request for Ishii Yuuichi, a stage actor who vanished right before the final performance of a play that had drawn attention for his hauntingly realistic acting. What happened to Yui and Yuuichi? And why were 333 people named "Ishii" chosen!?