Dan'ichirō Sanka (散華 団一郎, Sanka Danichiro) is the overprotective father of Rea. His love for his daughter is incestuous and pedophilic starting from when Rea was only little as she reminds him of his first wife.
His love for Rea is such that he completely ignores his second wife, Aria Sanka, and has never slept with her, which used to upset her a lot and now has made her bitter. Dan'ichirō has a habit of taking pictures of his daughter. On her birthdays he would take a nude shot of his daughter claiming that it's his right to record his daughter's growth. He also eliminates any of Rea's friends that tries to convince her that the act is not normal. He tells her that he is the only thing in this world that she ever needs. After being convinced by Chihiro about Rea's desire to live a life of a normal girl, he accepts Chihiro as Rea's protector. However, he also warns Chihiro that there should be no "sexual intercourse before marriage" possibly hinting that he accepts Chihiro as a man for his daughter. He later decides to leave for the United States to find a way to cure Rea.
He has black hair, eyebrows, and mustache. His eyes are brown. He also has four moles that go in a straight line down his forehead to the middle of his eyes. He usually dresses in a fancier manner, wearing slacks, loafers, button-up shirts, and sweater vests. He also constantly wears a pair of gloves because he is a huge germaphobe as well as allergic to animals, and he only takes them off when touching Rea.