Clerith fans looking for a canon, alternate dimension outlet where the lovers can be alive and happy together need look no further than the Kingdom Hearts series.
Kingdom Hearts, released in 2004 and directed by Tetsuya Nomura, featured cameos from a number of Final Fantasy characters. For Final Fantasy VII, this included Cloud and Aerith, as well as Yuffie and Cid (Tifa would not appear until Kingdom Hearts II).
In Kingdom Hearts 1, we meet Aerith in Traverse Town, where she helps Sora, the game’s protagonist. We meet Cloud in the Coliseum working with Hades, the antagonist from the film Hercules. When Sora asked why Cloud is cooperating with a villain, this exchange occurs.
Sora: So why did you go along with [Hades], anyway?
Kingdom Hearts
Cloud: I’m looking for someone. Hades promised to help.
Cloud: I tried to exploit the power of darkness, but it backfired.
Cloud: I fell into darkness, and couldn’t find the light.
Sora: You’ll find it. I’m searching, too.
Cloud: For your light? Don’t lose sight of it.
Remember that Hades is the Greek of the dead. Who is famously dead, whom Cloud mourns, and wants back at his side? The reference is unlikely to be a coincidence, but we don’t need to worry much about theory-crafting in Kingdom Hearts. Whether Cloud knows it or not, in this universe, Aerith is very much alive.
We don’t learn much about what happened between Cloud and Aerith, but the end credits montage includes this scene, where Cloud bashfully enters the library in Hallow Bastion, where Cid ushers him in. Aerith turns and sees him, and then the two are the only ones in the frame. Cloud looks shy, and Aerith does her classic pose where she leans in with her hands behind her back. (Hikaru Utada’s love song, Simple and Clean, is playing in the background.)

Thus is it implied that Cloud was searching for Aerith, and found her in the end. When asked about it in an interview, Nomura cryptically says as much:

――では、クラウドが探しているのは、やはりエアリスなんですか?
野村 どうなんでしょう? エアリスだったとしたら、エンディングでひとつの答えが出たことになる。そこはそうとも取れるようにしてあるというか。クラウドはやっぱり大好きなキャラクターなんで、自分としては、こうなんだという断定はあんまりしたくないかなと。ユーザーのかたがたの思い入れが強いでしょうから、みなさんの考える余地を残しておきたいんですよ
Question: Okay, then, so the person who Cloud is searching for is Aeris, right?Nomura: Well, what do you think? If indeed it was Aeris, then the bit in the ending was the answer. You might say it was made so that you can take it that way. Cloud is a popular character, and I don’t really want to decide myself, “yes he is like this.” Because players make strong conclusions by themselves, I want to leave room for everyone’s line of thought.
–Kingdom Hearts Ultimania, page 531
Nomura always prefers to be vague when discussing aspects related to the love triangle, so his hesitations in confirming one way or the other make sense – and also suggest that Nomura believes if he confirmed Cloud was looking for Aerith, that would be a meaningful statement. If Cloud was looking for Aerith and it wasn’t intended to be a big deal, he could have simply confirmed.

Question: What was the thought behind bringing back Aeris [in Kingdom Hearts]?
Official U.S. Playstation Magazine; October, 2002 (page 139-140)
Nomura: Yes, she died in Final Fantasy VII, but there’s no real relation to where she was at or what role she played in FFVII. There’s no relationship from FFVII to the Kingdom Hearts stories. I consider them separate stories. But if you play Kingdom Hearts, toward the end, some of the questions about the relationship between Cloud and Aeris in FFVII might be answered. It’s sort of like a side story, and this was an extra bonus that I wanted to give to players.
This hits hard. Nomura says that “questions about the relationship between Cloud and Aeris in FFVII might be answered” and it’s a like a side story that he wanted to give players. He specifies that the material that “answers questions” is “toward the end” – though the only scene with Cloud and Aeris at the end is, in fact, the very end – the credits scene.
So the only event Nomura can possibly be referring to is Cloud and Aeris’s reunion in the library. Remember that both of these quotes are only about Kingdom Hearts, not its sequels, which did not exist at the time of this interview.
To reiterate, this library reunion “answers questions” about Cloud and Aeris’s relationship “in FFVII”. The only thing this can mean is, they reunite once again. Recalling that in FFVII’s ending, Cloud expresses a desire to meet Aeris again in the Promised Land. Nomura wanted to give players this extra side story, showing that in another universe, Cloud and Aeris will be together. There is very little room for interpreting Nomura’s quote any other way.
Looking at Nomura’s descriptions of the Final Fantasy characters in the Kingdom Hearts Ultimania supports the same argument:

Cloud: FFVII’s main character, who even I have a strong attachment to. The single wing that appears when he uses the power of darkness is a homage to his eternal rival, Sephiroth. One answer for the scene during the credits with Aerith is that it is possible because this is a parallel universe, or so I think. [..]
Aerith: [..] This role was planned to be played by Aya from Parasite Eve until halfway through, but due to requests from staff who had worked on FFVII, Aerith was made to appear. Her story with Cloud grew from there. The developments in characters’ stories sometimes do come from exchanges like this.
The descriptions for both Cloud and Aeris specifically reference one another. In the case of Aerith’s profile, Nomura explains the origin of the decision to include her in Kingdom Hearts, and says “her story with Cloud grew from there.” That is, her subplot is meant to specifically be about Cloud. In Cloud’s profile, Nomura says their library reunion is possible because it’s a parallel universe, again, specifically referencing and justifying the two coming together.
In Kingdom Hearts II, while Aerith is working with Leon, Yuffie, and Cid to rebuild Hollow Bastion, Cloud is struggling with the darkness.
Cloud: I’ll get him. This time we settle it. Me, and the one who embodies all the darkness in me.
Kingdom Hearts II
Donald: I thought you looked kinda different, Cloud.
Cloud: If I do, it’s his fault.
Sora: Whose?
Cloud: Sephiroth. Tell me if you see him.
Sora: Okay. What’s he look like?
Cloud: Silver hair. Carries a long sword.
Sora: Sure. Well, be seeing you, Cloud.
Cloud: Be careful. He messes with your head, makes you think darkness is the only way.
Cloud then decides to leave to settle things, and he shares a farewell with Aerith.
Aerith: Is something wrong?
Kingdom Hearts II
Cloud: It’s nothing..
Aerith: Hmmm..
Cloud: I don’t want you involved.
Aerith: You mean… You don’t want me there when you go away again?
Cloud: I just… Listen. Even if I go far away, I’ll come back.
Aerith: Do you mean it?
Cloud: Yeah..
Aerith: See.. You don’t look so sure.
Well, okay. I understand. Go! Get things settled.
Cloud: Huh?!
Aerith: No matter how far away you are, once you find your light.. I’m sure it will lead you back here again.. Right?
Cloud: I supposed..
Aerith: So I’ll stay here and I’ll cheer for you. Okay, Cloud?
Cloud: Okay.
In this scene, Cloud needs to leave in order to settle the score with his darkness, embodied by Sephiroth. However, he tells Aeris that no matter how far he goes, he will return back to her. After thinking it over, Aeris chooses to support Cloud in his quest, and wait for his return. This dialogue seem to mirror a conversation in the original Final Fantasy VII, where Aeris leaves Cloud to handle Sephiroth but with a promise to “come back when it’s all over.”

In the Kingdom Heart II end credits, this time, we see Aeris waiting for Cloud to return. Cloud found her once at the end of Kingdom Hearts, so we have to imagine she has faith that he’ll return to her once again.

While Cloud and Aerith do not have any more scenes together as of yet in the Kingdom Hearts series, that doesn’t mean the series has nothing left to say on their relationship. In fact, the most surprising confirmation of Cloud and Aerith’s romance would come in Kingdom Hearts 2.8.
The credits here show a romantic montage of Disney couples. Various Disney princesses and their princes embrace lovingly, from Snow White, Sleeping Beauty, The Little Mermaid, and more. Even Mickey and Minnie Mouse appear together. And right in the middle of this romantic Disney montage is.. a scene of Cloud and Aerith together.
That’s right – Cloud and Aerith were included together in Kingdom Hearts‘ romantic collage of Disney love stories. No other Final Fantasy pairing has been shown in the series’ end credits like this. The order is this:
- Snow White/Prince Charming (Snow White)
- Aurora/Prince Phillip (Sleeping Beauty)
- Cinderella/Prince Charming (Cinderella)
- Ariel/Prince Eric (The Little Mermaid)
- Donald/Daisy (Disney original)
- Hercules/Meg (Hercules)
- Roxas/Namine (Kingdom Hearts)
- Cloud/Aerith (Final Fantasy VII)
- Peter Pan/Wendy (Peter Pan)
- Simba/Nala (The Lion King)
- Belle/Beast (Beauty & the Beast)
- Mulan/Li Shang (Mulan)
- Esmeralda/Phoebus (The Hunchback of Notre Dame)
- Aladdin/Jasmine (Aladdin)
- Mickey/Minnie (Disney)
- Sora/Kairi (Kingdom Hearts)
If that doesn’t confirm Cloud and Aerith’s romantic relationship in Kingdom Hearts, then nothing can.
On Tifa, Cloud’s Light, and Zack
In Kingdom Hearts 2, Tifa makes a special appearance. We first meet her solo, and she indicates to Sora that she is looking for Cloud. As Cloud challenges Sephiroth, Tifa appears, and offers Cloud her blinding light as he struggles against Sephiroth’s darkness.
Thus, Tifa takes the role as Cloud’s light in the series. But does that mean she, instead of Aerith, is Cloud’s romantic interest?
Not only is the answer no – Nomura suggests that Tifa isn’t even a real human.

Question: Speaking of Tifa, there’s an event where she talked to Cloud after beating Sephiroth.
Nomura: In Nojima-san’s scenario, it explained Cloud and Tifa’s connection more in-depth, but I trashed it. I thought it would be more interesting to let the gamers think about it. For example, “If Cloud’s darkness is Sephiroth, then Tifa is his light” – in that sense you can take it that Tifa isn’t really human. The reason Tifa doesn’t talk to anyone else besides Sora’s group may be because she doesn’t exist as a human. Of course, I also presented her in a way that she could also be a resident of Hollow Bastion, so I think you can freely think for yourself about her.
Nomura, Kingdom Hearts II Ultimania (source)
With Nomura’s quote in mind, Tifa might exist as some kind of spirit or symbol that assists Cloud, rather than an actual human. Of course, Nomura offers some room for interpretation as an olive branch (and even says he actually trashed an earlier draft from Nojima that would have offered more insight into whatever Cloud and Tifa’s connection was) but it’s difficult not to read this as canon and Nomura’s true thoughts on the matter.
In other words, whether or not Tifa is Cloud’s light has been a point of fan contention, but it doesn’t matter – she isn’t a human, so not Cloud’s love interest.
If Tifa is not a human and just a “light” for Cloud, then what is Aeris? Nojima chimes in.

Question: We heard from Mr. Nomura that you could see it as ‘if Sephiroth is Cloud’s darkness, then the light is Tifa’. Looking at it like that, what do you think Aerith’s position is?
Nojima: In my opinion, Aerith doesn’t belong to either light or darkness. Kind of like, she’s in another world, and can go to either if she wants to. She’s independent, not steeped in either light or darkness. To put it another way, she’s the most stable, having both light and darkness.
Nojima, interview
Nojima doesn’t touch the love triangle debate by asserting a role for Aeris specifically to Cloud, but the way he describes her as not belonging to either the light or the darkness is interesting. She’s independent, and stable – in other words, she’s very much human.

When Cloud battles Sephiroth, this exchange occurs:
Tifa: I will give you my light.
Kingdom Hearts II
Sephiroth: The light doesn’t suit you.
Cloud: For me…I don’t know.
Tifa offers Cloud her light, but it’s blinding. It could be that Cloud’s already too seeped in darkness, because Sephiroth mocks him, saying the light doesn’t suit him. Perhaps, like Aerith, Cloud belongs in neither (or both).
By the way, Zack also appears in Kingdom Hearts in the Birth By Sleep game. But there is no indication that there’s any connection between him and Aerith. Instead, he flirts with Aqua and asks her out on a date.

Thus, there is no love triangle at all in Kingdom Hearts. There is only Clerith.
Other Clerith Pieces in Kingdom Hearts

Aeris, who cherishes Cloud, is deeply worried about him!!


Working with Leon and the others to help rebuild Hollow Bastion. She is worried about Cloud, who is looking for Sephiroth.
Kingdom Hearts Character Files

Aerith
Kingdom Hearts 2 promotional article
A representative employed by Leon of the Hollow Bastion Restoration Committee. She is worried about Cloud, but Cloud is also worried about Aerith.
And finally, here’s a lovely little bit from the Kingdom Hearts Trading Card Game:


Aerith
Kingdom Hearts Trading Cards
All “Cloud” cards in play get +5 Support Value. If this card is discarded from your Friend Area, all “Cloud” cards in play must be discarded.
Wow – Cloud and Aerith’s trading cards are connected. If Aerith is lost (discarded), so too is Cloud. That certainly checks out!