The SOS Brigade, or SOS団, is a fictional club from the light novel series The Melancholy of Haruhi Suzumiya created by Nagaru Tanigawa. The club is formed by the main character, Haruhi Suzumiya, to seek out and investigate supernatural phenomena, including aliens, time travelers, and espers. The brigade consists of several key members, including Kyon, who serves as the narrator and Haruhi's reluctant friend, and Yuki Nagato, an alien interface. Other members include Mikuru Asahina, a time traveler, and Itsuki Koizumi, an esper. Together, they navigate various adventures while dealing with Haruhi's unpredictable nature.