His best friend. His crush. His entire class—turned into nothing but brains. One day, high school student Satoshi Tsutsuno wakes to find his classmates’ bodies missing, their brains preserved in a strange alien system. The culprit? A mysterious extraterrestrial calling herself "Professor A". She calmly explains: to protect Earth, the collective intelligence of Tsutsuno’s class—now reduced to a “brain cluster”—is essential. Left as the only physically intact student, Tsutsuno must now take on a harrowing mission to ensure their survival… and the planet’s. But what exactly is the test he’s been chosen for? And what secrets lie behind this twisted “salvation”? A shocking sci-fi suspense thriller from one of Shonen Jump’s most unpredictable minds!