"Boku-tachi no Shitai Sagashi" is a manga series that blends mystery, horror, and psychological elements. The narrative centers around a group of high school students who become entangled in a series of unsettling events after discovering a corpse in their school. This discovery sets off a chain reaction, drawing the students into a dark and dangerous investigation that uncovers secrets about their school, their peers, and themselves.

The protagonist, Aya Natsume, is a reserved and observant student who becomes the de facto leader of the group as they delve deeper into the mystery. Alongside her are several classmates, each with distinct personalities and backgrounds that influence their reactions to the unfolding events. These include the pragmatic and level-headed Kousuke, the impulsive and emotional Ryou, and the enigmatic and secretive Yui. As the group investigates, they encounter a series of increasingly bizarre and horrifying occurrences, including disappearances, cryptic messages, and supernatural phenomena.

The plot is driven by the students' efforts to uncover the truth behind the corpse and the strange happenings at their school. Their investigation reveals a connection to a series of urban legends and a shadowy figure known as the "Corpse Collector," who is rumored to be responsible for the deaths and disappearances. As the students piece together clues, they must confront their own fears, insecurities, and moral dilemmas, which are exacerbated by the growing tension and paranoia within the group.

The story is structured around a series of escalating mysteries, each revealing more about the central enigma while introducing new questions. The narrative maintains a steady pace, balancing moments of intense suspense with quieter, character-driven scenes that explore the psychological impact of the events on the students. Themes of trust, betrayal, and the fragility of human relationships are woven throughout the story, adding depth to the characters and their interactions.

As the series progresses, the line between reality and illusion becomes increasingly blurred, with the students questioning their perceptions and the nature of the threats they face. The climax brings the group face-to-face with the truth behind the Corpse Collector and the dark forces at play, leading to a resolution that ties together the various threads of the story while leaving room for lingering questions and ambiguity. The manga concludes with a mix of closure and open-endedness, reflecting the complexity of the narrative and the characters' journeys.