Ambiguously Brown: Mikaela, who claims to come from Louisiana. In fact, she's a princess from another land ravaged by the Crashers.
Anti-Hero: Slash and Soundwave become Type V (Type IV if you're generous) after Brash's littlestunt on Mikaela's homeworld.
Berserk Button: Subaru really hates to see her sister Airi in danger and will gladly beat someone to a pulp if he or she so much as slaps her.
Beware the Nice Ones: Though Subaru's drama teacher is generally easy-going, he did threaten to boot her from his class for assaulting several of his students (as he believes she had randomly snapped for no reason) before Akihiko took responsibility for her rampage (as he believes his casting of her as Tiana on a blind recommendation by a Covert Pervert within the class had eroded her sanity and caused her mental health to deteriorate) and demoted her to backstage duty for the production of The Princess and the Frog just to placate her and put her in a good mood again. To make sure Subaru doesn't go on another rampage, Daichi then enjoins the Covert Pervert from recommending her for any more roles and has Akihiko make his own casting decisions from now on.
Cerebus Syndrome: When the Band of Shi shows up, suddenly the Cures find themselves protecting various people from this four-person death machine, which can strike at any moment and is lethally competent (to the point where Ikuto is killed during rehearsals in episode 42 and would've stayed dead had Cure Rose Petals not shed Swiss Army Tears that fell on him).
Chekhov's Gun: That switchblade used to nearly gouge out Subaru's eye all those years ago? Turns out Tetsuo had dropped the switchblade in a panic when he saw a teacher pass by and Subaru had picked it up without knowing it would come in handy later on. It does—after knocking out her sister, who was under the influence of The Red Shoes (put on her by Slash), she holds her feet together with one hand and uses the switchblade in her other hand to cut the ribbons on both shoes, thus freeing her sister from the curse.
Color-Coded for Your Convenience: The Cures' outfits, all of which somehow evoke their color schemes. On a side note, Cures Ocean Breeze and Rose Petals have their own version of this trope, with Ocean Breeze wearing black tights and Rose Petals wearing white tights under their respective shorts as an indicator of who's the tomboy and who's the girly girl.
Cross-Cast Role: Every role Subaru's played for a drama department production has been male. This is much to her relief.
Demoted to Extra: Subaru gets demoted to backstage duty for The Princess and the Frog after Slash possessed her after a line-reading session, taking advantage of her worsening depression, and had her attack several of her drama classmates. This is much to her relief (she had previously been cast as Tiana for the same production).
Four Is Death: The Band of Shi, which has four members and has the Japanese word for four in its name. Predictably, this is where Cerebus Syndrome kicks in, as people are now in even greater danger of dying now that the Band of Shi has taken over from the original villain squad after all its members either died or turned good.
Good Scars, Evil Scars: Subaru has a permanent scar going down her left eye owing to the very same serious bullying incident that put her in a karate class in the first place.
Heel-Face Turn: Tetsuo, the one who tried to kill Subaru in the most serious bullying incident she ever fell victim to (and gave her a permanent scar over the eye he was trying to gouge out), didn't waste the 12 years he spent in reform school in connection to the incident, and he wants to prove it at his new school.
Imperial Stormtrooper Marksmanship Academy: The Band of Shi is lethally competent, but the Cures keep dragging or pushing their intended victims out of harm's way, to the point where Ikuto is their only actual casualty (though he does get better following the fight via Swiss Army Tears from Cure Rose Petals).
Kick the Dog: Slash once again hammers it in that she's not to be trusted in episode 25 when she curses a pair of red pointe shoes and, disguised as a new ballet student, puts them on Airi. Ironically, she's one of three members of the original villain squad to pull a Heel-Face Turn before the rest of the squad is eliminated. Compared to the other two dog-kicking machines in the squad (both of who were killed by a Kinomoto sister), she was lucky.
Lady and Knight: Airi and Subaru, respectively, during the Renaissance Fair episode.
Laser-Guided Karma: Sort of. Kai (the one that had previously recommended Subaru for the part of Tiana in The Princess and the Frog) gets cast as Haruhi in the drama department's production of The Melancholy of Haruhi Suzumiya: A Comedy in Seven Acts, but given the fact that both he and Haruhi have perverted streaks, even Subaru (who gets cast as Kyon, by the way) is rather split on whether Kai had been justly punished for nearly putting her in a dress or he's just Too Kinky to Torture.
Leotard of Power: Atsuko wears this during the colder months. Since it's a casual leotard, she wears it with a belt. Sometimes worn with a red skirt. Also worn by Cure Citrus, much to his chagrin.
Meaningful Name/Obviously Evil: The Band of Shi has four members, and they have a killing potential that the Cures had never dealt with before even when facing Metalic (who had claimed two casualties before dying, including Chief Mitsuhara and Cure Rose Petals, though the latter's death wasn't permanent).
Meganekko: Hiroaki is a male example, especially in Cure form. Another male example is Ikuto, who's stated in episode 35 to be of the Hideyoshi gender; interestingly, he'd been selected to dance as Hideyoshi himself months earlier for the class's production of a Baka and Test ballet.
Multi-Ethnic Name: After the events of episode 15, Cherri's full name is now Cherri Tanaka-Armstrong.
Non-Uniform Uniform: Subaru wears the male uniform's pants with her own uniform in lieu of a skirt; ironically, she still wears the standard-issue Mary Janes. Also, Hiroaki sometimes wears a blue tutu over his own school uniform.
One-Gender School: Arashi Mitsuhara attends an all-girls school; however, its parochial uniform is masculine in nature. This is much to Subaru's relief; she and the other Cures are forced to infiltrate the school as students when the Band of Shi sends one of their own to the school to capture Arashi, and given the fact that the Band of Shi takes no prisoners...
In-universe, Subaru is almost subjected to this for The Princess and the Frog in episode 26; fortunately for her, she gets demoted to backstage duty just as preparations get underway at the end of the same episode.
Sadistic Choice: From episode 30, after Mikaela's capture: "Either you... or her." The Cures are not amused to learn they have to give themselves up to save Mikaela, and being the Genre Savvy lot they are they Take a Third Option almost immediately.
Scars Are Forever: That scar over Subaru's left eye will never fade as long as she lives.
Skirt over Slacks: A blue tutu is part of Hiroaki's usual ensemble (even his school uniform at times).
Swiss Army Tears: The Cures have the ability to bring people back to life with their tears, though the only ones who get this treatment are Cure Rose Petals in episode 33 and Ikuto in episode 42.
Tights Under Shorts: Worn by Cures Ocean Breeze and Rose Petals. The latter is ironic, considering she does ballet and the rest of her Cure outfit is either outright balletic or just plain feminine and screaming of pink.
Tomboy and Girly Girl: The Kinomoto sisters, Subaru and Airi. Subaru is a martial arts freak, and Airi is a ballerina in training.
Who Wears Short Shorts?: Airi as Cure Rose Petals—and denim, at that! Of course, given the rest of her outfit and her ballet training, she's basically wearing the shorts to be ironic.