Dark Mousy

Dark is an entity passed on through the Niwa family to each new male once he reaches the age of 14 and experiences love. He was gone for 40 years due to the fact that Daisuke's grandfather Daiki, who was Dark before Daisuke, had an only daughter, Emiko. Being female, it was impossible for her to become Dark. He is the phantom thief who (in the anime) constantly steals cursed art pieces made by the Hikari family in order to seal their harmful powers (the only exception known is the Agate Links, which was an heirloom given as a gift from Daiki to Menou in the anime, but in the manga, it was stolen). Unlike Daisuke, who initially liked Risa, in most of the manga series Dark has fallen in love with Riku, the older and more defiant of the Harada twins. This crush on Riku lasts for quite awhile, or at least until the tenth book of the manga, where there are suggestions that Dark has faded from his crush with Riku, and is falling in love with Risa, instead. He uses Wiz as his wings, since his real ones, like Krad's and their magic, would hurt Daisuke. In the English version, Dark is known as the Phantom Thief Dark, while his whole name apparently being "Dark Mousy." Every time he uses his magic he gets closer and closer to his "true form." In the eighth book of the manga, Krad called Dark "Kokuyoku," referring (once again, in the manga) to Dark's "true name." This name, it seems, is one that Dark and Krad shared when they were both one figure. Taking this into consideration, there are hints both in the anime and manga that Dark and Krad were both an art piece made by the Hikari. In the last episode in the anime, Dark seals himself and Krad back into the painting where he and Krad were made. [Like the first part in the first episode.

Reputation

He is a known as Phantom Thief Dark (Kaitō Dāku in Japanese) and is a legendary thief of artworks (most of which, unknown to the public, have two common factors, one is that they belong to the Hikari family, the last of which is Satoshi Hiwatari, and that they contain magical properties). Who he is and where he is from are mysteries. For 300 years (400 in the manga) Dark’s power has been passed down through the male members of the Niwa family.

Though he always informs where, when and what he is going to 'steal', he never got caught by the police or any other human forces. Perhaps an invoke of his quirky saying "Honesty is the best policy." given in Manga number seven, to give honest warnings.

His demeanor is candid and confident, which is the complete opposite of Daisuke (shy and reserved.) He is well aware of his good looks and on the surface he could be seen as arrogant. It would be easy to dismiss the deeper, kinder side of his personality. Daisuke and Dark often fight against one another for control (resulting in some comedy relief.) He is also very flirtatious around girls. In other words, he's your typical bad boy. (shown in Volume 6 of the manga, where he states as the realisation that he doesn't know where the art he is supposed to steal is, "This is too much work. Maybe I'll go pick up some girls instead.")

He obviously seems to dislike Krad a lot (seeing as Krad has attempted to kill him and Daisuke several times; most likely in the past as well, he has encountered Krad before). Krad is Dark backwards because Krad is Dark's polar opposite in everything.

In the manga, he fell for Riku, but Riku labels him as a pervert as he stole her first kiss. He was rejected by Riku numerous times, and though it seemed to be not such a big deal on the surface, Dark's feelings were hurt by Riku's comments towards him.

Later in the manga, though, he is kissed by Risa, and turns back into Daisuke after she leaves (much to Daisuke's confusion) but in response to Daisuke's asking, he only reveals that he is an "endless existence" and refuses to say any more on the subject, which hints that Dark is more than he seems.

Later on, Dark went on a date with Risa, who was, of course, thrilled and excited. He then asked Risa a strange question: "If I was a monster, what would you do?" Risa hugged the phantom thief, saying that she would love him, triggering romantic feelings in Dark, who hastily runs away before he could turn back into Daisuke.

As Daisuke has noted, Dark's feelings towards Risa are slowly changing. The reason why Dark had gone to a date with Risa was to tell her not to pursue him anymore, as he would not be able to be together with her (seeing as Dark would disappear when Riku accepts the fact that Daisuke is Dark.)

Risa smiles at his rejection, and responded by saying: "I know that the great Phantom Thief Dark... can't get serious... about just one person." She then asks for one last ferris wheel ride, to which Dark agrees. But then there was a blackout, (caused by Argentine, the newest character) and Dark noticed that it was caused by magic that was very similar to Krad's. Knowing that Risa would be in danger if he continued to stay with her in the ferris wheel, he told her to stay there quietly until he comes back.

Risa told him that she will wait for him, and Dark speeds off. But then Argentine kidnaps Risa, leaving a card that said that he has taken Dark's "Sacred Maiden" away. Seeing the message, Dark turns furious, yelling that he won't forgive him (Argentine), and rips the card apart.

Dark - in the first episode - was escaping from Commander Satoshi and had to land on the Harada's balcony. Riku comes outside and is frightened by his sudden appearance, and as an attempt to shut her up (Because she was calling for Risa to help her), he "steals her first kiss." Ever since then Riku calls him a pervert. In that same episode Risa tells Riku of her love for "Dark-san" - which later leads to conflicts between the three.

During the course of the series, Risa and Dark go out on several dates, showing the developing relationship between the two. In a later episode when Risa goes out to help Dark, after he rescues her from falling from a rooftop and brings her to the Harada's house - he says "You remind me a lot of my Rika, she was the only woman I ever loved. I miss her to this very day. I'm afraid...I can't see you anymore."

His "only true love" is Rika - Risa and Riku's grandmother. (Oddly enough combining Risa and Riku's names spell out Rika. Which is ironic because he had relationships with both Risa and Riku.)