- Complete Monster: Makiko Kisugi, the Fear Ghoul, is a psychiatrist and Serial Killer who terrorized the city five years before the pillar of light was created. Finding the evolution drug inside Nagi's room at the hospital, Kisugi tested it on rats and herself, gaining the ability to sense the fear in others. Discovering that she liked the taste of fear, Kisugi began scaring her patients in the worst conditions, and murdered five young, strong-willed girls by removing their brains while they were still alive, and stalked a sixth would-be victim, because "their souls taste better". Having manipulated Pigeon, Kisugi broke Mo Murder's spine and threw him off the hospital balcony, killing him. The anime explores even more of her crimes, as she had injected her patients, and her own pregnant friend with the drug, just to see what would happen.
- They Wasted a Perfectly Good Character: It's almost comical how irrelevant Touka is to the plot other than being the host or a split personality of Boogiepop. It's telling when Takeda, who is kept deliberately Locked Out of the Loop and clearly intended to be her Satellite Love Interest, has more relevance to the plot than she does. It's worse in the anime where multiple episodes go by without her making an appearance or having any speaking lines.
- What an Idiot!: Masaki Taniguchi is a bit too trusting and never once questions why this mysterious girl that he met and started dating tells him nothing about herself and wants him to pretend to be Boogiepop. He has to be saved twice, once by his sister and once by the real Boogiepop, for him to realize what a mess he's gotten himself into.
YMMV / Boogiepop Series