DNAngel
Those two girls are Risa and Riku Harada. There twins and Risa (left) is the younger one who is exceptionally jealous of her older twin sister Riku (right). Riku is not on the competitive side. Here is another pic of the girls.
Riku is the one on the left and Risa is the one on the right.
Daisuke is your normal teenage boy until his fourteenth birthday. He had a huge crush on Risa but she gave him back his love letter on his birthday saying that he was too ordinary. Also on his fourteenth birthday, he turns into his alter ego, Dark Mousy, whenever he thinks of Risa. This is Daisuke Niwa.
This is Dark Mousy, Daisuke's alter ego form. He has a crush on Riku while Risa likes him. However when he thinks of Riku, he turns back into Daisuke. He is really a thief. 
This is Daisuke's loyal companion and pet, With (other pronounciations: Wiz, Wizu). With is really Dark Mousy's black wings. 
This is Satoshi Hiwatari. He considered the 'bad guy'. He is the cool, intelligent, and mysterious type. He has an alter ego form too, Krad(If you look carefully, Krad is Dark backwards). If you think the love urm...square is complicated enough, it get's more hard. I think secretly Satoshi likes Daisuke (not that I'm believing in shounen ai). He is a commanding offical of investigating Dark. 
This is Krad, Satoshi's alter ego form. He is actually the one who follows Dark. Satoshi follows Daisuke. Not much info is known on him. 
This is Takeshi Saehara, one of Daisuke's friends. His father is Police Inspector Saehara who is the one that chases after Dark. Always into adventurous stuff. 
This is Emiko Niwa, Daisuke's mother. She and her father, Jii-chan, have already knew that that Daisuke would change into Dark on Daisuk'e fourteenth birthday. It was a family thing. 
This is Jii-chan, Daisuke's grandfather. He had gone through the same thing as Daisuke when he was a child. After going through the main characters, here is the love stuff. Daisuke likes Risa, Risa, likes Dark, Dark likes Riku, and Riku partially likes Daisuke. Plus, I think Satoshi likes Daisuke. Later on, Daisuke likes Riku so everything is just a mixed up crazy world. =)
