In Nightmare Detective 2, a detective with the ability to enter people's dreams is hired to solve a series of mysterious suicides. As he delves deeper into the nightmares, he discovers a dark and twisted world filled with secrets and danger.

Nightmare Detective follows a mysterious detective who has the ability to enter people's dreams and help them face their nightmares. When a series of violent crimes occur in Tokyo, the detective is called in to assist the police. As he delves deeper into the dreams of the victims, he uncovers a web of hidden truths and dark secrets. With the clock ticking, he must navigate the surreal and dangerous dream world to catch the killer before more lives are lost.