Hanasaki Horie, father to protagonist Ao Horie, is a famous erotic novelist using his real name as his pen name. His notable works include *Promiscuous Lament* and *100 Words of Significance in Bed*. His profession profoundly shapes Ao's life, fostering her negative outlook on relationships. An alumnus of Tokyo University's Faculty of Literature, he ranked first in national mock exams during high school, earning the title "Prince of Literature."

He possesses a childlike appearance and stands approximately two heads tall, though flashbacks show him taller and slimmer in youth. Beyond writing, he pursues diverse ventures: producing energy drinks, managing an inn, writing scripts for TV anime, and publishing English conversation books with risqué content. He also authors romance guides under the alias "Floral Hori." Locally, he is known as "Doctor Pleasure," and his residence is nicknamed the "Pleasure Mansion."

His parenting style is overprotective and intrusive, particularly concerning Ao's social life after learning of classmate Takumi Kijima's romantic interest. He actively encourages their relationship, agreeing to Takumi's vocational school plans in Fukuoka and facilitating their relocation by arranging a new home. Later, during the "Adult Arc," he visits Fukuoka to monitor Ao's well-being and intervenes to prevent disruptions to her dates with Takumi.

Despite his professional focus on eroticism, his consistent, albeit meddlesome, support for Ao and Takumi's relationship demonstrates commitment to his daughter's personal growth. His academic background and multifaceted career underscore a complex personality beyond his literary persona.