Call of the Night summary: Appearing as an average middle schooler, Kou Yamori exhausts himself to keep up the image of a studious and agreeable friend. However, he eventually decides to leave school and shed his false persona, leading to bouts of insomnia and lackluster days. Despite finding solace in late-night solitude, Kou's restlessness alarms him. During a solitary stroll, Kou meets Nazuna Nanakusa - an inquisitive girl who helps him identify the root of his insomnia. Nazuna believes that true freedom is the cure, urging Kou to make changes in his life. Seeking to prove her point, Nazuna invites him to share her futon, and Kou is convinced her approach has worked. That is, until he pretends to slumber, and Nazuna sinks her teeth into his neck unexpectedly!