An uninhabited island, a towering pavilion, a ninth person who should not be there-- Sijima Island is said to have once been the site of research into a "doorway to another dimension. On this "island of urban legends," a series of murders take place, and the "great detectives" take on the challenge!

A high school student, Daichi Tenmei, whose father is a "great detective," and his classmate, Hitoshi Shiba, who has overwhelming insight and deductive powers. When these super high-school class unravel the mystery of the case, they will discover the meaning of truth.

Note: Based on the series of voiced animations on Youtube: @hundrednote100 + More