I had her for a little while; her name is Ivy. She was originally some kind of crystal princess, but when I rediscovered her and turned her into a Ballerina princess.
The Eclair arc did actually resolve some of my concerns going into it. Namely that this was not a mystery that Mikuru and Anna were even aware of. And Mikuru and Anna did get some clues to work with every week that lead them to a rather satisfying conclusion of using the scent of lilies to find the answer.
However, there was still a disconnect between the clues the audience had and the clues Mikuru and Anna had, which meant Mikuru and Anna's deductions of who Eclair could potentially be was still rather weak.
Anna and Mikuru didn't really figure out who could be Cure Eclair so much as just, figured out what could maybe get Cure Eclair to reveal herself. To a certain extent some of Anna and Mikuru's suspicions about the candidates boiled down to, "this is a girl about the right age in our social circle" rather than anything that specifically tied a girl to Eclair.
Meanwhile the audience was actually working off of things like, aesthetics (connections to lilies and butterflies), ideological stances, how Luluka treated them and how they interacted, or didn't with the magic side of things. Things that would be too vague to be in-universe clues most likely, or things that Anna and Mikuru were not around to witness. I think understand why the went about things this way, if Anna and Mikuru were solving the mystery, then it would take away the opportunity for the audience to figure it out so I think this was a good compromise, I just feel it makes Anna and Mikuru's connection to the plot and status as detectives feel a bit weak.
That being said, even before the start of the Eclair arc, and were able to consider the show from a meta-perspective (remembered this is still a Precure season obligated to making marketable decisions and also a Preschool show that had to make the resolution to it's mystery straight forward) it was pretty obvious who it was from about episode 9.
It was really obvious it was Kurea. Not that its a bad thing. Definitely not. The target audience is preschoolers, so it had to be a mystery they could solve. It was always meant to be someone obvious if you thought about it a little bit. Though as an adult I also had a lot of metatextual knowledge to fall back on that little kids don't.
1. Precure doesn't like vivid true green. We only ever get green when we also have a blue, and its usually more teal than Rei and Eliza's colors. Green doesn't sell well with little girls. So Rei and Eliza were just not happening. Neither of them looked that similar to Eclair either tbh.
2. Honestly, I thought it was Shiruku at first. But Shiruku basically had her episode warn about red herrings. If this wasn't a preschool show, I could have believed it could be a double fake out. But its babies first mystery. They gotta learn about fakeouts before they can learn double fakeouts.
So like that alone made Kurea the only candidate left, some thing that only became more clear as episodes passed because
3. In the end, Kurea is the only one who never got a precious item stolen. Her focus episode was actually more about Anna and time travel. Overall, Kurea had had very little development compared to the other candidates, which makes sense if they have different roles in the series from Kurea.
Eriza, Rei and Shiruku are side characters who are supposed to grab your attention from the start and make you want to engage with the mystery. Their primary role in the story will likely end with the Eclair reveal, so most of their character will be given to us beforehand (though I do fully expect them to get another episode or two in the future). Their role is to distract from Kurea.
Conversely Kurea is the mystery whose character unfolds after her secret identity is revealed. We don't know much about her because if we did it'd be obvious who she is (probably, we'll see how the next episodes actually play out). The fact that Kurea is the most boring candidate is likely the point.
Though, some other evidence really helped seal the deal.
The other big point against Rei and Eriza are their ages. Rei and Eriza are 15 and 17. This certainly doesn't disqualify them, but making 4 girls with an average age of 16, with Luluka as a 16 year old, it certainly makes the outlier ages suspicious.
It especially disqualified Rei once we found out that Eclair used to live at the detective agency. It would be weird if the granddaughter of the school chairwoman lived somewhere other than the school, specifically the place Mikuru moved to, and not get hinted at, at all. It's hard to see Luluka and Rei having a strong dynamic.
Eriza is honestly a perfectly reasonable candidate, if not for her color pallet, and the fact her flighty energetic personality may push the dynamic of the group a bit too far to the high-energy side. And unlike Shiruku and Rei who have places to be when Eclair was a detective, Eriza doesn't really. But she also didn't have much selling her as a potential cure either besides her interest in detectives.
Shiruku is a reasonable guess, in all fairness. Actually the most hinted option, but its for that reason combined with the don't make assumptions platitudes that turns the hints for, into hints against. Shiruku is visually the once closest to Eclair in my opinion, and Kurea hadn't had any real focus yet so wasn't truly on the table at the time of episode 9. Which is why when her episode is titled "Don't make assumptions" the most obvious assumption the audience can be making at this point is that Shiruku is Cure Eclair. I was making that assumption. And this being a preschool show means we can take this statement at face value that the assumption that Shiruku is Cure Eclair is incorrect. There is also the fact that Shiruku as an actress probably didn't have time to be a detective on top of that.
The target demographic of this show is doing a lot of heavy lifting here. But appeal to the target demographic is the underlying reasoning for a lot of Precure's writing decisions and that's not something I can easily ignore while watching.
And for points to Kurea, while Shiruku got her focus episode before Kurea, Kurea and Eriza were actually the earliest introduced candidates, debuting in episode 2. It makes sense to establish the real Eclair as a character as early as possible even if she wasn't the main focus of that episode.
Also, Kurea had a connection to Anna's future through Anna's birthday cake. A connection to the themes of the show none of the other candidates have.
Speaking of which, Kurea works at a patisserie, and her Cure name is Eclair. No other Eclair candidate has a connection to sweets. While the name Eclair could certainly be a red-herring clue, it certainly helps set Kurea apart from the other candidates. (Also does the average Japanese preschooler even know that Eclairs are sweets? Because that was not a sweet I was familiar with at 5 and it hasn't been brought up in show yet. Its super obvious to an adult audience but is it obvious to the kids? I genuinely do not know.)
Rei and Eriza were obviously there to flesh out the candidate pool rather than serious options, they hinted at Shiruku TOO hard to where it's obvious her role is to be a misdirection, and conversely Kurea was understated to the point there was obviously more going on.
Now to be fair I was viewing it way more through the lens of "what makes the most sense for the writers" when I think a lot of people were trying to piece together in universe clues and not narrative function. In which case. Yes. Meitantei removed from any context was somewhat ambiguous about who it could be for a good portion of the first half of the season. Though, after episode 23 it was all but explicitly confirmed to be Eclair, so that way the little kids could have the opportunity to figure it out first. But I think in general a lot of people were overthinking this mystery instead of looking at it through the lens of "is this intuitive to a 5 year old".
And the intuitive to a 5 year old answer is definitely "Blue Cure with butterfly in her hair named after sweets is girl from the patisserie with blue hair with a butterfly in it". Many of them may get fooled by Shiruku (which is definitely the point), or decide that it's Rei or Eriza because they liked them best. But Kurea kinda is the obvious answer to 5 year old logic. And I am looking forward to actually getting to know Kurea now that she has her memories back.