"Chi-Sui Maru" is a supernatural mystery anime centered around a cursed fishing boat and the eerie events surrounding it. The narrative unfolds in a small coastal town where the titular vessel, the Chi-Sui Maru, is discovered adrift after vanishing decades earlier under mysterious circumstances. The boat is found with no crew aboard, yet it appears as though time has stood still, with personal belongings and equipment left untouched. The discovery draws the attention of a group of individuals, each with their own connection to the boat or the town’s history.

The protagonist, a young journalist named Haruto, arrives in the town to investigate the legend of the Chi-Sui Maru, driven by a personal interest in uncovering the truth behind its disappearance. Alongside Haruto, the story introduces a local historian, Ayaka, who has spent years researching the boat’s history, and a fisherman named Kenta, whose family has ties to the original crew. As the trio delves deeper into the mystery, they uncover a series of unsettling events tied to the boat, including strange occurrences in the town and unexplained phenomena experienced by those who come into contact with the vessel.

The plot intertwines past and present, revealing the tragic fate of the original crew through flashbacks and fragmented memories. The crew’s disappearance is linked to a series of supernatural forces, including vengeful spirits and ancient maritime curses. As Haruto, Ayaka, and Kenta piece together the clues, they find themselves targeted by the same malevolent forces that doomed the Chi-Sui Maru. The story builds tension through a series of escalating encounters with the supernatural, culminating in a confrontation that forces the characters to confront the boat’s dark legacy and their own personal demons.

The anime explores themes of guilt, redemption, and the lingering impact of the past, with each character grappling with their own motivations and fears. The Chi-Sui Maru serves as both a physical and symbolic vessel for these themes, embodying the town’s collective trauma and the unresolved mysteries of its history. The narrative maintains a steady pace, balancing moments of suspense with character-driven drama, and concludes with a resolution that ties together the threads of the story while leaving room for interpretation regarding the supernatural elements.