Akeanan is an outstanding school in all aspects: education, sports… and secrets.

Traffic comes to Akeanan to look for his sister Fah, who disappeared months prior and with neither the police nor the school finding any trace of her. In the course of his investigation, Traffic finds himself in Room 4/6 and meets the class outsiders: bad boy Andrew, quiet lad Highlight, strong and powerful Title, friendly and playful Jim Bae, and academic genius Buntad.

Traffic gets an invitation from their teacher to join this group of boys in the secret shadow society known as Blacklist, which is said to be dedicated to investigating the mysterious occurrences in their school.

Unified in Blacklist, the school outsiders will find out not just what happened to Fah but will also uncover the deep dark secrets of Akeanan School.