"Grope - Yami no naka no Kotori-tachi" is a short anime series that revolves around a group of high school students who find themselves trapped in a mysterious, dark underground facility. The narrative begins with the protagonist, Aoi, waking up in an unfamiliar, dimly lit room with no memory of how she arrived there. She soon encounters other students from her school, including the reserved and intelligent Ritsu, the cheerful and optimistic Yuka, and the cautious and pragmatic Shou. Together, they must navigate the eerie and labyrinthine environment, uncovering clues about their predicament while avoiding the dangers lurking in the shadows.

As the group explores the facility, they discover that it is filled with cryptic messages, locked doors, and strange mechanisms that require cooperation and problem-solving to overcome. The tension escalates as they encounter unsettling phenomena, such as flickering lights, distant whispers, and the occasional presence of an unseen entity. The characters' personalities and relationships are tested as they grapple with fear, mistrust, and the pressure to escape. Aoi emerges as a determined leader, driven by a desire to protect her friends and uncover the truth behind their imprisonment.

The series delves into themes of survival, trust, and the psychological toll of isolation. Each character's backstory is gradually revealed, shedding light on their motivations and fears. The narrative builds toward a climactic confrontation with the forces controlling the facility, culminating in a resolution that ties together the mysteries introduced throughout the story. While the series is brief, it effectively creates an atmosphere of suspense and intrigue, focusing on the dynamics between the characters and their struggle to escape the darkness that surrounds them.