"Twi-Yaba" is a supernatural mystery anime set in a secluded rural town surrounded by dense forests and steeped in local folklore. The narrative centers on a group of high school students who become entangled in a series of inexplicable events after discovering an ancient shrine hidden deep within the woods. The shrine, believed to be a gateway to another realm, is tied to a centuries-old legend about a deity known as the "Twilight Weaver," said to manipulate time and space.

The protagonist, Aoi Hoshino, is a reserved yet observant student with a keen interest in local history. Aoi’s life takes a dramatic turn when a classmate, Renji Kuroda, vanishes during a school trip near the shrine. As Aoi investigates Renji’s disappearance, she uncovers cryptic symbols and fragmented memories shared by other students, hinting at a recurring cycle of events tied to the shrine. The group soon realizes that they are part of a larger, interconnected fate, with each member harboring a unique connection to the Twilight Weaver.

Key characters include Haruka Miyamoto, a pragmatic and resourceful friend of Aoi, who provides logical insights into the unfolding mystery; Sora Tachibana, a mysterious transfer student with knowledge of the shrine’s history; and Kaito Fujimoto, a skeptic whose skepticism is challenged as the supernatural phenomena intensify. Together, they navigate a labyrinth of time loops, shifting realities, and cryptic visions, each revelation bringing them closer to understanding the true nature of the Twilight Weaver and their own roles in the cycle.

The plot unfolds through a series of interconnected arcs, blending elements of psychological suspense and supernatural horror. The students’ investigations lead them to confront their deepest fears and unresolved traumas, as the shrine’s influence grows stronger. The narrative explores themes of fate, memory, and the consequences of tampering with forces beyond human comprehension. As the story progresses, the line between reality and illusion blurs, culminating in a climactic confrontation with the Twilight Weaver that challenges the characters’ perceptions of time and existence.