A high school girl named Haruhi Suzumiya is obsessed with the supernatural and forms the SOS Brigade to investigate mysterious happenings. Narrated by her classmate Kyon, who had given up his belief in the supernatural before meeting her, the story follows as Haruhi and those around her are drawn into surreal situations and a world full of fantasies. After Haruhi forms her club, she forcefully drafts Kyon, who decides to stay in the club to protect other helpless victims of Haruhi’s “voluntary arrests”. As the series progress, Haruhi recruits three additional members into her club, without realizing they are the very things she is seeking. Among them are Yuki Nagato, a silent bibliophile who is actually an artificial human created by the extraterrestrial Integrated Data Entity; shy and timid Mikuru Asahina who is also a time traveler; and the always smiling Itsuki Koizumi who is always willing give in to Haruhi’s strange demands and is actually one of many espers in an organization known as The Agency.
Each of the members, except Kyon, are secret agents who were sent to observe Haruhi because she herself has unique powers she is unaware of. Haruhi possesses a superhuman control over the universe, so when she becomes dissatisfied with reality, she subconsciously creates a new universe—one more to her liking—and attempts to switch over, thus leading to the destruction of the current universe. In order to prevent this, the members of Haruhi’s club spend their time attempting to keep their god-like leader entertained, hold her powers in check, and maintain the illusion of a normal life.