Onoda Aki, Sobue Ryou, and Inohara Yuuta, are childhood friends attending the elementary school. They investigate the Shinto shrine in the island cave, where they meet Fureru, a yellow tailed hedgehog, and adopt it as a pet. When they touch each other and hear their inner voices, they are caught by Fureru's magical power within the fur. In the aftermath, they can "no longer hear their inner voices and they are supposed to touch each other". As the power becomes clear, their friendship begins to waver. Ten years later, Fureru and the trio move to Takadanobaba in Shinjuku. There, they defend Asakawa Nana and Kamozawa Juri from a stalker. Source: Wikipedia