Kusaide-kun harbors a deep obsession with Nakashima-sensei, who reminds him of a beloved teacher from his past. Driven by the news of her upcoming transfer, he indulges in a vivid, erotic fantasy of a forbidden encounter in the school infirmary. However, the dream is abruptly interrupted by a train announcement, revealing that the entire experience was merely a daydream, fueling his determination to make his fantasies a reality.