"Slight Fever Syndrome" is a psychological drama that explores themes of identity, memory, and the fragility of human relationships. The narrative centers on Haruto Aizawa, a high school student who begins experiencing strange, recurring dreams that blur the line between reality and illusion. These dreams are tied to a mysterious condition known as "Slight Fever Syndrome," which causes individuals to relive fragmented memories and emotions from their past. As Haruto delves deeper into his condition, he discovers that his dreams are connected to a tragic incident involving his childhood friend, Yui Nakamura, who disappeared years ago under unexplained circumstances. The plot unfolds as Haruto uncovers suppressed memories of his past, revealing that Yui’s disappearance was linked to a series of experiments conducted by a clandestine organization. This organization sought to manipulate human consciousness by inducing Slight Fever Syndrome in select individuals, using their memories as a testing ground for advanced psychological research. Haruto’s journey becomes a race against time as he attempts to piece together the truth about Yui’s fate while grappling with the ethical implications of the experiments and their impact on his own psyche. Key characters include Haruto’s classmate, Rina Takahashi, who becomes an ally in his quest for answers. Rina’s pragmatic demeanor contrasts with Haruto’s emotional vulnerability, creating a dynamic partnership. Another pivotal figure is Dr. Kenta Mori, a former researcher involved in the experiments, who provides cryptic clues about the organization’s motives and the true nature of Slight Fever Syndrome. The series also introduces a shadowy antagonist, known only as "The Director," who orchestrates the experiments and manipulates events from behind the scenes. The story is structured around Haruto’s gradual unraveling of the mystery, with each episode revealing new layers of the conspiracy and its effects on the characters. Flashbacks and dream sequences are used extensively to convey the fragmented nature of memory and the psychological toll of the syndrome. The narrative builds toward a climactic confrontation between Haruto and The Director, culminating in a resolution that questions the boundaries of reality and the consequences of tampering with human consciousness.