These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Cure Ace herself. Is she a really badass and awesome new addition to the team or a badly shoehorned-in character who makes no sense? Is her being noticeably older than the Cures when transformed and noticeably younger when not appealing or off-putting? Is she a cool Aloof Ally who just wants to help the girls to get stronger however indirectly or is she a smug and condescending girl who does nothing to help the Cures but takes the credit anyway? Fans seem to be rather split on this.
Mana is either awesome and refreshing for a magical girl protagonist or a Mary Sue and a spotlight hog.
And of course, the whole season itself. Fans are so heavily divided over it.
Is the Non-Serial Movie canon, or not? While Cure Ace's inclusion is quite tacked on, and the future everyone visited is lacking some individuals (mainly Joe and Regina), it's still possible for it to happen within the series' canon. Word of God even went on to clarify some contradictions, and revealed that there was supposed to be a Foreshadowing to the movie in one of earlier episodes. There are also several Canon Immigrant from the movie in the last three episodes.
Counterpart Comparison: To Aikatsu, which is an idol anime and aired four months before the show. The two have many similarities, namely the shared card suit motif, and each has a red-ribbon blonde-haired girl. There have been crossover fanarts featuring the two shows, with Regina and Ichigo being the most prominent.
Creator's Pet: The staff have mentioned their emotional attachment to Mana. Some storyline elements were also dropped to provide more focus on her.
Draco in Leather Pants: Regina quickly became this for the fanbase. In hindsight, they were onto something with that.
Aguri's body is set on fire when she transform into Cure Ace. Portgas D. Ace had fire as his devil fruit powers. Cure Ace is voiced by Rie Kugimiya, who voiced Shana with the blazing eyes and flaming red hair - Cure Ace has these, too. Ace's weapon - no, not thatAce - is called "Love Kiss Rouge". The first red Cure was Cure Rouge, who had fire powers.
Alice has been drawing comparisons with Batman. Then in episode 25, her butler Sebastian makes a Batman-like Cure costume. And he was supposed to be the Alfred stand-in!
Iron Woobie: Makopi, whose Woobie-quotience is enough to break the Woobie-o-meter several times. She's a refugee from a magical kingdom which was destroyed down to the spiritual level. She's a questing-knight in search of her lost queen, who might have been dead all along. She's a Magical Girl Warrior fighting enemies made of the evil-defining aspect of humanity. And before she meet the other Cures, she's without allies except Davie.
Anything that can be applied to Makopi can be applied to fellow Knight of Trump Jonathan Klondike, known on Earth as Joe Okada. The poor man doesn't even have a fairy.
Alice is already drawing comparisons to Batman, what with being a rich "superhero" with a skilled butler.
At one point, during the ending Dancing Theme, the camera focuses on Cure Diamond during a rather... silly-looking part of the ending choreography. This led many Pretty Cure fans to believe that this meant Rikka was a bad dancer. Thus, the "Rikka dancing" meme was born.
Speaking of Rikka, fanartists seem to like portraying her as a Yandere towards Mana, usually with Makoto (or more recently, Regina) involved. Interestingly, this is what they did to the last season's Reika, who also had blue hair and had a very close Cure friend.
Makotonigiri.explanation A scene in episode 22 depicts Makoto eating an onigiri with a somewhat funny expression. Japanese Image Boards then began to edit this scene to ridiculous extent. Then the meme was brought to Global Image Boards and the rest is history.
Memetic Molester: Quite a few fans find Joe to be quite creepy, given his flirtatious comments and how touchy-feely he tends to be.
Moral Event Horizon: Regina's involvement in the destruction of Makopi's homeworld may not have been a MEH after all, but Bel is revealed in episode 46 to have unambiguously crossed the MEH when he tried to corrupt Marie-Ange, which ultimately caused her to split in two and become Madoka Aguri and Regina.
Narm: When a Jikochuu is made from a Victim of the Week, the way the heart bursts out of the person's chest resembles the visual effect when a cartoon character is madly in love with someone.
Not to mention that their appearances are as a rule more stupid/cute than actually remotely scary at all.
Nightmare Fuel: The destruction of the Trump Kingdom and the fate of its citizens. The younger kids probably won't understand what it's like to lose your home and your folks, but it makes the older kids (and the older audience) cringe.
Replacement Scrappy: Aguri/Cure Ace was this for Regina fans. And there was a video of a girl crying when Ace is shown not to be Regina to fuel more hate. Thankfully, fans have mellowed down on her since she reveals more about herself.
The Scrappy: While she does have a few fans, Mana is the most widely disliked lead Cure so far, mostly due to her Canon Sue and Spotlight-Stealing Squad tendencies, as well as being an admittedCreator's Pet. The team finishers that involve the Magical Lovely Pad and its harp form, are basically just the other Cures giving Heart their powers, who defeats the Monster of the Week herself (though not so much for Royal Lovely Straight Flush). It gets to the point where Doki Doki ends the same way as Digimon Xros Wars: The Young Hunters Leaping Through Time (whose lead, Taigiru, is also considered the worst lead of the Digimon Franchise) as in she takes everyone else's powers, along with the three sacred treasures, and fights the final battle alone in a new form. She's even considered one of the main reasons Doki Doki is so unpopular.
Aguri/Cure Ace is immensely disliked, and is another reason for Doki Doki's unpopularity, due to to how she was introduced, her bratty Drill Sargent Nature, and the fact that she ends up replacing Makoto as the expositor for most of the remaining Myth Arc. Made worse by the fact that she tried to kill an amesiac and powerless Ira. Turns out it was a test, but fans still hate her for it.
Explanation on how she's introduced. A new Cure is always a previously established character, and with that is sometimes either royality or a girl who made a Heel-Face Turn. Aguri is despised for breaking that tradition and replacing a fan favorite. It looked like it was making Regina the new Cure. It is sadly thrown out when King Jikochu makes her evil again. Then Cure Ace shows up and easily deafeats Regina, who is Put on a Bus for nearly the entire second half of Doki Doki. In the same episode it's quickly revealed that Ace is an Elementary School girl named Aguri, a new character who appears out of nowhere. Who then proceeds to do nothing but tell off the girls for several episodes.
Thanks to episode 36, Yashima gets a lot of hate for introducing her boyfriend in front of Raquel (who gets Precocious Crush on her), all while thanking him.
Regina is also becoming this for certain Mana/Rikka shippers, some of whom have complained that the focus put on Regina and Mana's interactions necessitates Mana's devoted childhood friend Rikka, who was already getting shafted somewhat in favor of Makoto, getting pushed aside even more in order to give focus to Mana's growing relationship with Regina.
And after Episode 26, Ira is getting a lot of heat from Mana/Rikka shippers.
Nikaidou is the enemy, if not THE enemy for shippers of every Les Yay couples that involves Mana. The hate began when one of movie promotional opening shows him blushing when Mana gets too close on him. It got worse in the last two episodes, where he starts using First Name Basis on Mana (which only her family, fellow Cures, and Regina do so) and spends most of his time talking about Mana. The real kicker? Most of his appearances in the series itself don't have anything to do with Mana.
Fan-Preferred Couple: Mana/Rikka was a popular ship among fans before the show even aired. When Mana and Rikka were shown to have a great deal of Les Yay between them in canon (i.e. episode 2), the ship became even more popular, to the point of pretty much being this series' Hibiki/Kanade.
Judging by the amount of fanworks alone, Ira/Rikka is now the most popular hetero couple of Doki Doki, and one of the most popular of the franchise as a whole. To illustrate: in Pixiv, Ira/Rikka has 1000+ artworks. Other hetero couples of Doki Doki only reach one-tenth of it at most.
Foe Yay Shipping: Mana/Regina has become a popular choice. Ira/Rikka had become popular as well since episode 4, and became much more popular after episode 26.
Launcher of a Thousand Ships: Aida Mana is proving to be quite possibly the most shipped person in the series' history. Most of the girls that fans ship her with include Rikka, Alice, Makoto, Regina, and Aguri. And then there are jokes abound about how Dokidoki is a stealth Harem Series. Pixiv even has a tag specified for her harem (マナハーレム).
Crossover Ship: She is also shipped with previous season's Miyuki, thanks to the All-Stars New Stage movie.
Before Mana, Makoto used to be shipped a lot with the other Cures, Marie-Ange, and even Davi in her manager form.
OT 3: It is either Makoto/Mana/Rikka, Regina/Mana/Rikka, Regina/Mana/Makoto.
Shocking Swerve: Regina turning evil again and Cure Ace being someone we've never met.
They Wasted a Perfectly Good Character: While everyone aside from Mana, Regina and Cure Ace can be seen as this, Alice in particular gets the short end of the stick, as it can seem like her only purpose on the show is to use Rosetta Reflection.
Visual Effects of Awesome: Aside from the series having relatively good animation throughout, Cure Ace's transformation takes this to a ridiculous level. It's almost near movie like when it comes to the animation quality and is considered to be the coolest looking transformation in the franchise to date. See it here in HD.
Uncanny Valley: Ai-chan just looks weird, being more humanoid-looking than other Pretty Cure fairies.