Other hints include mentions to her pokemon or more metaphorical hints. We will have a look at those here.

✦ XY022 - Going for the Gold! When they visit an aquarium, they are met with a group of Piplup and one comes close to the group. After Serena and Bonnie mention how cute the species is, Ash mentions something like "the one I met was not that sweet". And by that point the only Piplup he met that fit that description was Dawn's.
It's also funny to notice that in all of XY, this is the only reference we have to a character from past seasons other than Professor Oak and Delia at the very end.

✦ JN048- A Close Call... Practically! The Fake Pikachu Team Rocket builds this episode is pretty much a perfect copy of Ash's, except for the fact that instead of saying "Pikachu" it says "Hikachu... And like, cmon, how can I not read too much into that?? Specially with Dawn's jap nickname being Pikari? They're one and the same, Ash's number one partner!

Also known in the fandom as the Pearlshipping anthem. High Touch is second japanese opening for the Diamond & Pearl series and is credited as being sung by Ash and Dawn themselves, as the ones who sing this opening are no one other that Matsumoto Rica and Toyoguchi Megumi.

Below, I will transcribe and translate the song lyrics and then we will analise its meanings.

Things about this song relevant to pearlshipping: How often they talk about how they understand one another, to the point of not even needing words, just high fiving one another ♥
How they fight but always make up at the end. How they are always supporting one another and how being together make them more confident in their dreams.

But in special, verses like

There are a lot of things I want to say to you

No matter where I go...
Your smile is always there!

This journey goes forever on, but
Always... Your smile is with me!

Lastly, is interesting to note that the lyrics for this song were written by Akihito Toda, who also wrote a lot of the older OPs and EDs of the anime, with Mezase Pokemon Master, Ok!, Spurt and Type:Wild being worth mention, as those are very iconic songs from Ash's POV.
For Dawn to get a song shared with Ash, written by the "Ash POV song writer" while no other character had that honour? That's amazing on its own.

Dawn's theme song and the first ending of DPani. At first sung by Grin, it was later re-recorded with Toyoguchi Megumi singing in-character.

Again, like High Touch, this one talks about how "as long they're together, things will be fine". In this one, as Dawn theme song, is likely that the "one" Dawn talks about in here is just Piplup or any of her partner pokemon.

However, themes from this song will be repeated in some songs post DP and that's where things get interesting.

DPani's 2nd ending. Not sung by any character from the anime, but that doesn't mean that we can't over analyse it too!

Once again a song mostly focused on never giving up on your dreams.

However the verse

Are you well? How are your friends?
The smell of the wind, the color of the sky
Are they the same?

At first assumed to be a Piplup song, the 3rd ending of DPani later got a cover sung by Toyoguchi Megumi, Hikari/Dawn herself. Taking that into account we can assume that the song is about her too to an extent.

While the song talks about how someone wants to apologize to someone else, is interesting how certain phrases like "Will I be able to say it?" and Should I say it?", specially after the phrase "I really like you more than anyone else" give it a more romantic tone. I wonder, what is thing Dawn wants to say so badly. To someone she shares everything with?

Lastly, we have this verse:

Whistle, whistleistle, in the sunset
I said goodbye
Whistle, whistleistle, the north wind
Somehow, it feels a bit cold today

With a title that means "in your heart!", for an ending marking the last 10 episodes of DP, this song is very bittersweet.

Talking about a dream just barely out of reach, about how time doesn't stop for no one and about "feelings untold".

We'll always, always be special friends

I like you because you worked harder than anyone else
When we convey our feelings, a miracle will definitely happen

This song also seem to have some indirect references to Dawn. With mentions of a shining, radiant person (Hikari means light in japanese). But ignoring the puns, it could also be about Ash and his too bright personality.

Ok, so this one is not a song made for pokemon, but rather a cover. And yet. For pokemon to go and deliberately pick a romantic song for the ending of the 11th movie (when that rarely happened before and after DP)? Interesting.

And once again, this song focuses on talking about parting ways with a loved one, about missing a loved one, about keeping going despite not being together. Are you seeing a theme??

Movie 12 ending song. And funnily enough, another very heavily romantic song.

And once again focused on the theme of separation, of wanting to be together but time coming in the way.

With excerpts such as

You are the one
As an irreplaceable friend
And someone more than that
You gently give me the strength to move forward
For that, I love you

Another thing of note in this song is this verse:

Thousands of flower petals
Come pouring down on us, ooh

Another very romantic-y song. However, I feel like this one connects the less with the movie13 (and Ash and Dawn relationship) than the previous movies.

Despite this song's lack of connection with Ash and Dawn as the others, the verse "Now, the antenna of my heart is resonating // Could this possibly be what is called 'love'?" is very nice in how it portrays both Ash and Dawn's denseness with the subject.

My favorite song that I like to read too much into ♥

Ending song for the final movie from the DP era. Pretty much a goodbye to the gen 4 anime and fittingly so, it also feels like a bitterweet goodbye to Dawn and pearlshipping.

From the "Our relationship is a casual one to the point that we can talk about anything // We've been together a long time, but nothing's changed, has it?" verse and how that ties in perfectly with the themes of High Touch.

With the "How would it be if you were here? Would you laugh with me?" and "It seems like you're even further and further away than I imagined // Someday you'll disappear with someone" tying in with the previous themes of separation and still caring for one another.

The verses "We've been acting it out for so many years, casted as best friends and "The syndrome called "friendship" is a perpetual labyrinth without exit" once again talking about a friendship that wants to be more than that.

How "I want the smile reflected deep in my eyes to only belong to me" makes a direct reference to "Always... // Your smile is with me! and "No matter where I go... // Your smile is always there!".

And at the end of the song, a mention of how the person of interest seems to "sparkle". As if made of light.

And we didn't even mentioned the title of the song! Ice cream syndrome. Like the Ice cream Ash and Dawn shared all the way back in DP064.

BW first opening. And this song seems to be a direct narration of Ash's feelings in Unova. A new place, with new people, filled with new adventures.

It's interesting how this song is the first Opening post DP and includes the following excerpt:

"If I listen closely, I hear a nostalgic voice
A voice from the future
It's always praying for me
"You'll be all right!
Somehow it'll be all right!
Everyone will be all right!"

And then afterwards we get the following:

Wind, carry my voice
Carry my feelings
To that person in a distant town
"I'll be all right!
I'll be totally all right!
I'm not alone, I have my friends, so I'll be all right!

Lastly, this song just like High Touch! was written by Akihito Toda, so we can say with some certainity that the use of Dawn's catchphrase here was not coincidental.

Now this one. Movie20 ending song. This one is my favorite.

First there is the fact this is a lyrics version of Oracion, a song originally created for the 1st DP movie. So we already have some connection with Dawn from the get-go.

But then you look at the lyrics and get things like the verse "kimi no egao yappari ichiban sukinanda" being almost indentical to the verse "yappari ichiban daisuki sa" from Ashita wa kitto.

The verse "Motto tsuyoku naretta toki ni wa" sounding almost like a reply to the "motto motto tsuyoku naru kara" from Kaze no message.

How the running and smile and dreams, that voice from the past/future, are all themes that make a comeback in this ending. Something consistently used in the DP endings as well. Even if this song is not about Ash and Dawn, it sure make lots of references to the DP series.

Insert songs

For instance, the opening song Ready Go! (which notoriously has Daijobu as part of its lyrics) was used as an insert song during DP027, coincidentally the same episode in which Dawn got her first ribbon!

May be, May not

But if you wanna have fun and not be objective at all and read too much into stuff with me, here we go!

Disclaimer: For those I'll not be including the full lyrics, only the parts I think are more releveant, but I'll be linking articles on each song with translations so you can take your own conclusion.

✦ BW song - Natsumeku Sakamichi
Lyrics + translation on Bulbapedia
The final song for the BW season. And it's once again one of those songs that feels just too romantic for Pokemon, but hey, maybe they were hinting at AshXIris, I'm not scrapping that idea. But I would like to emphasize the constant use of "そばにいるから" (Because I'll be by your side) in the chorus and how that connects beautifully to Dawn's theme song Kimi no soba de (By your side).

✦ BW song - Sora / Koe
Lyrics + translation of Koe
Sora version of this song doesn't really make much reference to SatoHika if I'm being honest, but I like how both songs are about this person from the past that the singer misses and how at the end of Koe, we get the line "君と優しさと // 光あるかぎり", which translates to "As long as there's you and kindness // As long as there's light".
And I know I'm picking at straws here, but remember Yajirushi ni Natte? Remember how that used the word light and made it about Hikari? So I can do the same here~

✦ BW song - Memories
Lyrics + translation
Another overly romantic song and I can twist to be about Dawn because once again it focuses on talking about someone from the past (1); talks about someone's smile, like High Touch and many other songs from DP loved to do (2); and ends with a "Daijobu" at the end (3)!

✦ BW song - Egao
Lyrics + translation
There's another Hikari name drop here, "いつだって一番のひかり" (You're always a shining beacon in my life), more remiscing the past, more mentions of one's smile and another kimi no soba de expression usage "いつも君のそばにいるから" (because I'm always by your side).

✦ XY song - Tweedia
Lyrics + Translation
Being completely honest, this song is more likely about Serena and Ash's relationship and how she discovered a goal of herself because of him. But the excerpt

When painful moments and bitter memories overlap
They look like petals and make me laugh

✦ XY song - Posuto ni Koe o Nageirete
Lyrics + translation
This one is very romantic and is totally about Volcanion and Magearna's relationship, I know that!!
BUT! The little bit at the beggining that talks about how they always fight and make up, with the exact same wording as the ones Dawn uses in High Touch!

HT: Kenka mata naori mata kenka

PKN: Kenka shitte mo nakanaori

✦ XY song - Candy Girl
Lyrics + translation
This one is not an "official pokemon song", instead just a song that was featured in the same album that released Dori Dori, but it has been adopted into the fandom as a Serena song. Specifically an SerenaxAsh song.
Then why am I including this here? Cause a lot of the phrases in this song are almost indentical to phrases sung by Dawn herself in High Touch!

CG: Tokidoki kenka mo shite
Nakanaori wa zettai, yo

HT: Kenka naka naori kenka mata kenka

CG: kimi no koto wo
Oh, Oh, mamotte agetai

HT: mamotte kureru yo

✦ SM song - Mirai Connection
Lyrics + translation on Bulbapedia
Another one that I gotta reiterate that I have reading comprehension and say that I know it is about Ash and Poipole's relationship!!
But...... We got another Hikari name drop "差し込んだ光" (The light beaming throught) and the excerpt:

未来コネクション　つまずいても大丈夫さ
手を繋げば　ほらキラキラ輝く

Future connection, it's alright if you stumble and fall
If we join our hands, look at how brilliantly you shine

And to top all that, the final line of this song is "太陽みたいな　キミが大好きだ" (Bright like the sun, I love you) and you know what is bright like the sun? That's rigth, Light!

Hints in promotional material such as posters, opening and ending sequences.

Openings and Endings

✦ High Touch
Despite being the one with the song they sing together, it is pretty chill with their interactions in it. The most we have is a sequence where Dawn pushes Ash and he gives her a thumbs up and some high fives.

✦ Kimi no soba de
This one is about Dawn, so as expected there's not many sequences focused on anyone else. However is interesting to notice that in the few slideshows from the beggining (very 2000s too, love how ugly it looks today), there's 2 pictures with a zoom-in of Pikachu's ear and of Ash's hat. All that while Piplup is nowhere to be seen in the sequence.

✦ Kaze no message
Now this one is interesting!

At the 29 seconds mark, after we get a sequence of Ash with Pikachu being showered by cherry blossom petals (which could be read as a reference to Dawn in its pink color, but I'm not reaching that far), we get this sequence:

And is interesting that the light staircase visual was used like this, because back in the second Johto OP, Aim to be a Pokemon Master (Whiteberry version), there's a sequence with Ash climbing a light staircase exactly like this one!

Oh, and immediately after that we get Ash dressed in the cheering outftit that sadly he never used in the actual anime; followed by Dawn in her own cheerleader outfit.

Promotional art

---

Domino's pizza ad

This story is about a boy, Satoshi and
Pocket Monsters, and
Their friendship, adventures and meetings

This is one of the things that came out of it lol

But some fun stuff that came off it that adds to Pearlshipping is the fact that a lot of merchandise that came from it or just after Project Pochama seems to give a special focus on Pikachu and Pochama as a duo.

Which is interesting cause you would think Eevee would have preference but Piplup really earned his spot as "Pikachu's partner".

Sinnoh Jumpscare

Little things that don't really add to Ash and Dawn's relationship but that do connect to Sinnoh or Gen 4 and that alone makes me giddy.

✦ Sorrel and Verity
Sorrel and Verity are characters that appeared in the 20th Pokemon Movie - I choose you! The funny thing about those characters is that, despite the movie being a celebration of 20 years of Pokemon (specifically of the release of Red&Blue games), those two characters are from Sinnoh!! With Verity being from Twinleaf (like Dawn!) and Sorrel being from Veilstone (like Paul!!).

Not only that, but Verity shares a starter with Dawn and Sorrel has a Lucario (like Ash). And then there's the fact the ending song for that Movie is Oracion, a song connected with Movie10 and even the nightmare Ash had in this movie is seemingly based off an scratched idea of a nightmare that he was supposed to have in the Movie10 too!

That's a lot of Sinnoh!

✦ Dia
Dia is a character that appeared in the SM100-101 (Battling the Beast Within! - Parallel Friendships!). He is from an alternate universe and his younger self is based off Red.

His connection to Red and by consequence Ash, and his name being short for Diamond (as in, Diamond & Pearl) is interesting. So many names to choose from for this Ash foil and they went with a name that always makes me think of Sinnoh.

✦ A ripple in time
A lil short video meant to promote a collab between Pokemon and Daniel Arsham (dont ask, I dont know). The video uses Ash's original design, features Brock and Misty and plenty of the Kanto-Johto characters and is very much meant to be a Gen 1-2 nostalgia thing.
And yet..... Cynthia of all people is there!

✦ Aura
In the special episode Distant Blue Sky!, that takes place in perhaps the same universe as the AU movies (I'm not sure), with an Ash that seems to closely follow Takeshi Shudo's original ideas for the anime, we still have that Ash using aura! A concept originally introduced in the DP games.

In short, is funny to me how the anime tried to time and time again to push Ash back into Kanto one way or another and everytime they couldn't keep Sinnoh too far from him.