"Higanjima X" is a supernatural action-horror anime series that serves as a sequel to the original "Higanjima" story. The narrative centers on Akira Miyamoto, a high school student who, after a year of searching, reunites with his long-lost brother, Atsushi. Atsushi had disappeared two years prior under mysterious circumstances and is now living on Higanjima, a remote island shrouded in dark secrets. Upon arriving on the island, Akira discovers that Higanjima is overrun by vampires led by a powerful and ruthless leader known as Kyoichi Miyagawa. These vampires are not the typical supernatural beings but are instead humans transformed into bloodthirsty creatures through a mysterious virus.

Akira, along with a group of survivors, including Rei, Yukie, and Ken, must navigate the treacherous island, battling vampires and uncovering the truth behind the virus and the island's curse. The group faces constant danger as they attempt to find a way to escape Higanjima while also confronting their own fears and moral dilemmas. Akira's determination to save his brother and the others drives much of the plot, but his resolve is tested as the true nature of the vampires and the island's dark history are revealed.

The series explores themes of survival, loyalty, and the blurred line between humanity and monstrosity. Akira's growth as a leader and his evolving relationship with Atsushi are central to the story, as are the dynamics within the group of survivors. The vampires, particularly Kyoichi, are portrayed as complex antagonists with their own motivations and tragic backstories, adding depth to the conflict. The narrative is punctuated by intense action sequences, tense confrontations, and moments of emotional weight as the characters grapple with the harsh realities of their situation.

"Higanjima X" builds upon the foundation of its predecessor, expanding the lore of Higanjima and delving deeper into the origins of the vampire plague. The series maintains a fast-paced and suspenseful tone, with each episode advancing the plot and raising the stakes for the characters. The interplay between the human survivors and the vampire threat creates a compelling dynamic, driving the story toward its climactic resolution.