In this episode, Yayoi and Keitaro explore the ruins of Castle H, an S-rank haunted location. Yayoi explains the dangers of such places, including the risk of being trapped or cursed. Despite the oppressive atmosphere, they press on, guided by an old woman who appears unexpectedly. She shares a tragic tale from the late 1500s about the fall of the castle and the fate of the women left behind.

As they continue, Keitaro hears footsteps and senses a presence. Yayoi gives him a protective item for self-defense. Suddenly, Yayoi vanishes, leaving Keitaro alone and surrounded by spirits. He feels paralyzed but manages to break free when he realizes he’s been cursed.

Keitaro finds himself at the waterfall, the focal point of the area’s ghost story. He recalls Yayoi’s words about being a great partner and blames himself for letting his guard down, leading him to believe Yayoi might be dead. The episode ends on a cliffhanger, stating that Keitaro is on his own to face this terrifying foe.