Emiko Niwa is the mother of the protagonist of the series, Daisuke Niwa and a member of the Niwa family. She is responsible for the traps in the Niwa home, her son's thief training, and the preparations for Dark's heists.
Emiko has red hair and eyes like all main members of the Niwa family. Her hair is shoulder-length and straight. She wears a variety of outfits, skirts, and frilly aprons, and is considered to be beautiful.
In the anime, Emiko's hair and eyes are light brown.
Passionate and bold, she isn't afraid to speak her mind or pursue her goals. Emiko often uses her bubbly personality to distract people from her disguises or sleights of hand; thus, she is also shrewd and a master of deception.
She is protective of her family, quick to suspect the Hikari and to comically threaten violence towards those who harm or kidnap her son.
Emiko is the daughter of Daiki Niwa, the tamer of Phantom Thief Dark 40 years prior to the series. Her mother died when Emiko was very young, and she blamed herself for taking away her father's most precious person, in addition to being unable to fulfill the Niwa duties of transforming into Dark due to being female. She cried out to Dark to make her a phantom thief; he heard but did not respond.
Throughout her youth, Emiko was popular with boys. However, whenever they asked her out, she would question whether they would father her future son and inadvertently scared them away.
When she was 23 and in college, she was again approached by several men who wanted to ask her out on St. White's Day. She rejected them, explaining why each one was not a suitable candidate to father her future son. But the men stubbornly pressed forward, accidentally pushing her off the platform and in the path of the approaching train. Kosuke Niwa arrived and pulled her back to safety.
When Kosuke offered her a handkerchief, Emiko saw entangled with it a white ribbon, similar to the ribbon that she anonymously received one year ago. He admitted to being her mystery sender and asked a question that no other man had asked: Why did she want to have a son? Emiko happily declared that she wanted to be the mother of the Phantom Thief Dark.
Dark explains her feelings to Daisuke over 14 years later; she did not want her child to feel the sadness that she felt growing up.
Eventually Emiko married Kosuke and gave birth to Daisuke, whom she trained to inherit the Niwa family duties. She admits later in the series that she should have explained the reason for his crimes sooner, but is interrupted when Daisuke mentions that collecting Hikari artworks is also a hobby for her.
In the anime Edit
Emiko participates in mysterious, occult rituals where she and Daiki dress in dark robes and ask for spirits’ assistance in the basement of their house. On Daisuke’s 14th birthday, she insists on how important that day’s ritual is, without indicating it’s for Dark’s awakening. She is aware of Daisuke’s feelings for his classmate Risa, much to the boy’s surprise.
Daisuke Niwa Edit
Emiko likes her son dearly. She trained him to be a great thief since he was young.
Emiko acts in a very affectionate way with her husband.
Dark plainly calls her "Emiko". Dark once said that Emiko is his "mother" who gave birth to him[reference needed].
Emiko and her father are partners, as Emiko managed the family and Daiki is a reference when it comes to artworks and hosting Dark.
Emiko won a beauty pageant and was known as the "Angel of Azumano".
In Daisuke's birthday omake, Emiko does not know how old Dark is, speculating that he might be 3000 years old.