After moving into the quiet town of Hinamizawa, Maebara Keiichi spends his days blissfully in school often playing games with his local friends. However, appearances can be deceiving. One fateful day, Keiichi stumbles upon news of a murder that had occurred in Hinamizawa. From this point on, horrific events unfold in front of Keiichi, as he soon learns his close friends may not be all that they seem. Based on the amateur mystery game by 07th Expansion, the story is told in a series of different scenarios.

Eve Polastri on jännityksettömään työhönsä kyllästynyt MI5:n turvallisuusviranomainen. Villanelle taas on taitava, mieleltään oikukas palkkamurhaaja. Kun Evelle tarjoutuu tilaisuus lähteä jäljittämään Villanellea, saa alkunsa vaarallinen kissa ja hiiri -leikki, jossa roolit alkavat pian kääntyä päälaelleen.

Gerard Edling is a well-to-do lecturer, an expert in kinesics (the science of body language) and a former prosecutor with vast experience. Horst Zeiger is a shy young man, an outsider, a computer geek and... a totally unpredictable murderer. When one of them intends to commit a crime, the other, known for being able to decipher any criminal and solve any case, tries to prevent it. Unfortunately, the result of their duel is a macabre spectacle, broadcast online to thousands of viewers...