Foe Yay / Ho Yay is all over the place in D.N.Angel. In episode 14 Satoshi rescues Daisuke from the pool and gives him (or in the manga, Wiz/With disguised as Daisuke) CPR after he nearly drowns with all of the girls who were watching getting embarrassed/excited and calling it a "boy to boy kiss!" (complete with Daisuke blushing over the implications and fainting- note there was no disgust at all), Satoshi and Daisuke are cast as the prince and princess in an all-male version of a fairytale for a school play where Snow Means Love is abundant, Daisuke initially transforms with a picture of Risa; Satoshi transforms with a picture of Daisuke, etc.
The Yaoi Fangirls made a comeback when Daisuke fell ill at school and Satoshi carried him bridal-style to the infirmary. One of their female classmates is blushing and gushing in the background that "They look so good together!!", weirding out the boy standing next to her.
Episode 4 of the anime has a lot of Satoshi/Daisuke moments such as the dream Daisuke has about Satoshi and how Dark accuses him of being in love with Satoshi which Daisuke denies, this scene where Satoshi sneaks up on Daisuke when he's looking at information on him online and questions him about his motives, and when Daisuke and Satoshi get trapped in the school's freezer when Satoshi deliberately sabotages it, in an attempt to force Daisuke to reveal himself as Dark. He does, but this also sets off Satoshi's transformation into his alter-ego, Krad. This also provides an excuse to have Daisuke and Satoshi huddling together for warmth to up the Ho Yay quotient even more. And not to mention when Daisuke expresses concern for Satoshi when he experiences pain upon trying to transform into Krad, runs to his side, and rubs his back. And also catches Satoshi in his arms. And Satoshi acts in a Tsundere manner towards Daisuke, pushing him away, and telling him he doesn't need him as a friend. Daisuke wonders why Satoshi doesn't want to be his friend since Satoshi always went out of his way to talk to him. And after they have their battle as Dark and Krad the first thing Daisuke does when he wakes up is ask if Satoshi's alright. Also, after their battle Satoshi is nice enough to give Daisuke a ride to school. In the limo Daisuke asks Satoshi if he's alright again.
In episode 11 Satoshi appears again and Daisuke worries about him after the temple is flooded.
In episode 12 Daisuke worries about Satoshi again after Krad has taken over Satoshi's body and acts relieved when he sees that he's okay.
In episode 13 Daisuke faints after becoming Dark and when he wakes up he sees Satoshi who had been watching over him while he was unconscious. And Daisuke again expresses worry over Satoshi's condition.
In episode 17 Daisuke and Satoshi are at the beach on a school trip and Satoshi helps dig Daisuke out of the sand. Some girls watching end up mistaking them for being gay for each other. Daisuke tries to deny it and asks Satoshi to agree with him but Satoshi smiles and says "Who knows?" causing the girls to squeal.
In episode 19 Daisuke and Satoshi are cast as the princess and prince of the school play respectively with the girls getting excited when they hear Satoshi and Daisuke will have to perform love scenes.
In episode 20 Daisuke and Satoshi are shown practicing for the play with rose petals in the background and romantic music and Daisuke is shown blushing when Satoshi tells him "We will be together forever."
In episode 21 Daisuke and Satoshi are supposed to practice their love scene but Daisuke has a cold and Risa warns Riku that Daisuke might get taken from her by Satoshi if she's not careful. Satoshi walks right into Daisuke's room to see him and worries about him, getting close, touching him and looking deep into his eyes when warning him that he should be careful. And he continues to do so right up until Riku comes in. Also, when Daisuke gets put in a trance/taken away by Freedert Satoshi is shown to be looking for him and acting really concerned with a worried look in his eyes. He even runs after him in a hurry and asks him if he's alright when he finds him but it turns out to be Dark. He's shown looking really worried and whispering Daisuke's name.
In episode 24 Satoshi worries about Daisuke again and tries his best to save Daisuke from his prison in the painting.
The CPR was used a second time in the manga when Daisuke nearly drowns again, which means Satoshi has to give him CPR again only Dark takes over Daisuke's body before Satoshi can, and punches him. He then has a fit over the implications.
The time in chapter 9 when Satoshi dresses up as a woman and Dark gets about half an inch away from liplocking him before realizing that he's a guy.
And after that Dark tells Satoshi "You would have been just my type if you were a girl".
There's also the very first chapter/episode, when Satoshi pushes Daisuke (who currently has Dark's face) onto the ground and practically straddles him while getting into his face and telling him he's waited his entire life for this. ...Like we said, all over the place.
In a Returning The Handkerchief moment (which is usually used for romantic Ship Tease situations) Satoshi lends his handkerchief to Daisuke in the first volume; Daisuke gives it back in the second volume during a chapter that begins to explore Satoshi's character more. In Volume 3 of the manga, Satoshi finds Daisuke's white ribbon (that he meant to give to Risa), but assumes that the owner of the ribbon is Risa because she just walked past him when he found it. He spends two chapters looking for her, and when he does find her, she's crying to Dark after getting upset over seeing Daisuke (and Riku together). Satoshi ends up standing by a wall nearby them, staring at the ribbon.
There's also a particular section of a relatively recent chapter of the manga that is extremely similar to love confessions in other manga. Satoshi tells Daisuke that he had resigned himself to hating everyone, but then he says that for some reason, he couldn't bring himself to hate him. Cue a montage of their big moments together, ending in a gigantic picture of Daisuke laughing, while Satoshi thinks "And that was the only thing that truly...ever brought me joy."
Satoshi is wearing Daisuke's jacket at that point, by the way. He keeps it for the entire volume, and at the end even says "Thanks for the jacket" and walks away without giving it back.
Satoshi tries to keep emotional distance from Daisuke to prevent his alter ego from appearing. He knows that Daisuke isn't a normal student as his training to be a thief allows him to unlock very hard devices but Daisuke seems to just want Satoshi to open up to him more.
In the anime (episode 1), they add some (totally on purpose) dialogue in the art room that goes like this:
Daisuke: Oh, where did everyone go? They're so mean not to come and help.
Satoshi: I told them not to.
Satoshi: I wanted us to be alone.
Satoshi: Are you free tonight?
Satoshi: Or do you have something... important to do?
Daisuke: *stammers* Oh, well, today's my birthday.
Satoshi: I see. Oh well, it can't be helped.
And throughout the manga and anime there are TONS of dialogue like these that the only reason why you can even pretend it's two straight guys is because one's a policeman and the other's a thief.
Dark once had a bet with Satoshi that, IIRC, went something like this: "If I manage to steal my next target, you'll stop getting close to Daisuke" - the implication being that if Satoshi manages to stop him, Dai's all his. The next day at school, Satoshi asks Daisuke whether he's aware of the bet - by pushing him up against a wall and leaning in very close.
Implications still stand, but was that not more of a bet to make sure that Satoshi wouldn't ARREST Daisuke in Dark's place? Though Satoshi does have a habit of handcuffing Dark to things...
The two have an epic moment in the most recent cliffhanger, with Satoshi breaking down while Daisuke hugs him. Of course given the context Satoshi begging Daisuke to turn into Dark so things can be over and then Satoshi putting a gun to his own temple when Daisuke rejects him it's also going into Tear Jerker territory.
Satoshi seems to care more about Daisuke than any other person, and his transformation (which is triggered by feelings of love) happens when Daisuke gets too close.
In the last episode Daisuke leaps on to Satoshi, pinning him to the ground and says he wants him to live. Now, Satoshi is shirtless for the scene, so that's a big plus. Also, they cry together. And Daisuke later allows an injured Satoshi to lean on him while holding onto him and asks him if he's alright again. Satoshi was also shirtless so Daisuke put his jacket on him and Satoshi asked if he could keep the jacket and Satoshi is determined to live after Daisuke told him to. They also share a smile.
In the anime, it is hinted that Satoshi may have romantic feelings for Daisuke. When this is brought up, he doesn't openly confess to anything, though he never denies the accusations either. If anything, he encourages the idea, which has led to the source of much confusion regarding his motives. It has even been stated outright by Dark that Daisuke is the one who causes Satoshi to turn into Krad. Krad himself has also hinted at Satoshi possibly wanting more than a friendship from Daisuke at least once in the anime, and more than twice in the manga. In any case, he at least wants to be close to Daisuke despite the danger of Krad to both of them.
Can't forget Satoshi and his Super-Powered Evil Side Krad: Whenever we see the two together alone, it's generally Krad cuddling Satoshi from behind, or declaring that "You are my everything, Satoshi-sama". Would be incredibly sweet if not for the fact that Krad is also a homicidal blonde angel, who only really wants Satoshi for his body by which he actually means to take over Satoshi's body, as he's some kind of incorporeal spirit and Satoshi is his "host". Well. Hopefully that's all he means by it. Krad also tremendously enjoys reminding Satoshi that he (Satoshi) is not allowed to get close to anyone, and especially not his sworn enemy/best and only friend/possibly love interest.
In episode 23 Krad gets really close to Satoshi to whisper in his ear "I care for you so much and yet you always look away."
And then there's the Foe Yay-tasticness that is Krad/Dark, like how in episode 12 at one point Krad gets really close to Dark's face and tells him "We haven't seen each other in such a long time yet you still give me such a cold attitude?" when Dark tells him he doesn't even want to see his face.
And in episode 24 Dark and Krad are fighting and Krad pins Dark to the ground while standing atop him with a wide grin on his face and later lifts Risa up with his power because she was trying to intrude on an "important conversation that Dark-san and I (Krad) are having."
In episode 26 when Krad shows up again he gets really close to Dark's face and tells him "I have been waiting for you, Dark Mousy!!"
On the subject of Dark/Daisuke... One plot involves Daisuke having to save Dark after Satoshi traps him inside of a dream world.
Also, Dark loves to tease Daisuke and is genuinely nice to him at some points and in episode 10 expresses a lot of concern when Daisuke's soul is stolen by a magical violin and does everything in his power to get him back, worrying that he wouldn't ever be able to see Daisuke again.
Also this picture in chapter 1 of Dark and Daisuke.
And in episode 21 Daisuke has been put in a trance which makes Dark act really concerned and tries to get Daisuke to snap out of it.
In episode 22 Dark says in a Tsundere fashion that he didn't come after Daisuke for him but for himself (Dark) while getting really close to a blushing Daisuke's face.
In episode 23 Risa says that Dark wants to help Daisuke. And when Towa says she found out the location of the sword so that they may find Daisuke Dark is shown grabbing Towa and screaming at her "What?! Where?! Towa!!"
In episode 24 Dark fights Krad for the sword because he wants to in Krad's words "liberate" Daisuke from his prison so much. And Dark is glad that Satoshi is trying his best to save Daisuke from inside his prison in the painting. And he even goes inside the painting to search for Daisuke, calling out Daisuke's name. And once he finds him he grabs hold of him in both arms despite Daisuke struggling to get away as they're flying.
In episode 26 Dark tells Daisuke "I won't forget you." And Daisuke later tells Dark "I'm inside of you. I won't forget about you either. I never will." In response to this Dark appears to cry.
Dark/Daisuke: Dark tells Rokuto: (talking about Daisuke)
Rokuto: "He was supposed to be mine!"
Dark: "You have such bad taste and such wild delusions. Too bad for you. He belongs to me."
Saga Keiji, a producer from Saga entertainment, towards Daisuke. In chapter 9 he has his men bring Daisuke to his office to speak with him about participating in a commercial. Once Daisuke seems more relaxed about staying, Keiji orders his men to leave the room. Once the door closes, Keiji tells Daisuke to ‘strip' so he can try on a costume for the commercial. To prevent him from bolting, Keiji has his bodyguard Hunabashi restrain Daisuke as an overeager Keiji tackles Daisuke to the sofa, straddles him and starts to take Daisuke’s clothes off. However, Keiji gets a bit excited from seeing Daisuke's embarrassed face that he starts to take his own clothes off. He stops when Hunabashi whacks him on the head with a book. Then we hear Keiji going into fanboy mode as he's measuring Daisuke complete with lines like "Oh ho! Look at his curved lines! It looks good over here too! Great! Great! Great! Oh ho! Let's see this side!" As he's doing this his men thinks that he sounds like an 'old pervert'. And his Ho Yay towards Daisuke continues throughout the rest of the time we see him in the manga.
In episode 15 Risa does the Security Cling to Riku and they have a tendency to get really close to each other's faces when arguing or talking.
In episode 22 Riku smiles and tells Risa "Right now, you're so cute that if my hands weren't tied I'd hug you."
In episode 26 Risa is extremely worried when Riku goes missing and searches for her slapping her when she finds her telling her she was worried. Risa then hugs Riku and they stay in that position for a while.
Hiwatari Sr has many, very creepy moments with Satoshi, his adopted son. From "I missed seeing your face" to "I'm doing this for you, my precious son" to "It's because I'm worried about you" to "I don't want to lose you" to "One has to take good care of their tools" to a scene in Stage Four (manga volume 15) in which he forces Satoshi to transform while holding him down over a table - yes, the entire has very disturbing rape undertones.
Saehara/Daisuke: They get along really well, are best friends, and Saehara really likes to invade Daisuke's personal space and put his arm around him. In episode 8 Daisuke blushes when Saehara smiles at him and Saehara buys Daisuke an ice cream.
All the girls in Daisuke's school towards Ayaka Hatori in episode 7. She has tons of fangirls who blush and wear looks of great admiration in her presence.
In episode 25 Satoshi's adopted father calls Krad "my cute little servant" after Krad asks for them to get along.
No matter how you look at it, every consequential character in this series has a counterpart of the same sex. Dark and Krad CANNOT EXIST without the bodies of Daisuke and Satoshi respectively (take that how you will). Alternately, Dark and Krad have the 'two sides of the same coin' thing going for each other, as do Daisuke and Satoshi. ie they complete each other. Add adorable twin school girls Riku and Risa to the equation... this series is a breeding ground for homosexual subtext.