Batman: Mystery of the Batwoman

Last of the three DCAU movies based on Batman: The Animated Series, Batman: Mystery of the Batwoman concerns Batman's investigation of the titular new Bat in town. While Batman deals with this one distraction, three new women appear in Bruce Wayne's life - Rocky, a young scientist working with Wayne Industries; Sonia, a new police officer assigned to the force; and Kathy, the spoiled daughter of crime boss Carlton Duquesne. Soon, all three become prime suspects in the case of the Batwoman... which is not too far from the truth at all.

Tropes used in Batman: Mystery of the Batwoman include:

Action Girl: Batwoman, but Sonia is an accomplished police detective before the film even starts. The Penguin's Bodyguard Babes count as well.
Actor Allusion - Like her voice actress Elisa Gabriellia, Sonia has a beauty spot on her left cheek.
Art Shift - This film was made after the "revamp," which was an artistic redesign between the original animated series and The New Batman Adventures, and was drawn in the style of the latter. Rupert Thorne had never appeared after the original revamp, so a new design had to be created to match his character with the art-style of the rest of the film. Though more "streamlined," it is nigh-identical to his previous design.
Batwoman - A re-imagining of the character, originally created in 1956. Her original identity is alluded to with Kathy Duquesne, whose name is phonetically similar to the original Kathy Kane.
Bittersweet Ending: Predominantly more sweet than bitter, but it is not without its sadness. Rocky gets her fiance out of jail and Kathy gets her family out of the mob business, but Sonia is forced off the police force.
The Chanteuse: The unnamed singer who performs "Betcha Neva" in the Iceberg Lounge.
Collective Identity - Batwoman is all three of the suspected women, working together to pose as a single multi-skilled crime-fighter.
Blonde, Brunette, Redhead - Rocky, Kathy and Sonia.
Cast as a Mask: Kyra Sedgwick plays Batwoman. But the three women sharing her identity are all played by different actresses.
Clear My Loved One's Name: Rocky is trying to do this for her fiancee, Kevin.
Cute Clumsy Girl - Rocky.
Dating Catwoman - Bruce goes out with Kathy, daughter of notorious crime boss Carlton Duquesne, a few times. Given that he is the Trope Namer, this is not surprising.
Deadpan Snarker - Alfred, as per usual, and Tim Drake gets in a few good ones as well.
Digging Yourself Deeper - Roxanne in this bit:

Bruce: Working late again?
Roxanne: Yeah. Fortunately my boyfriend is very understanding. What about yours? *pause* Girlfriend, I mean! Of course, girlfriend! I mean, considering your reputation and- NOT that it's bad or anything or even any of my business, because it's not, I was just curious! *stops suddenly* How red is my face?
Bruce: (cheerfully) Crimson.

Disney Villain Death - Bane falls into the fires on the ship below him, seemingly killing him. Anyone who has watched Batman Beyond will know that this did not kill him.
Distaff Counterpart
Doppelganger Attack - Sort of. The remaining two Batwomen pull a Big Damn Heroes against the bad guys.
Dynamic Entry - How Bane introduces himself to Batwoman/ Kathy. By smashing out of the crate she was about to put the bomb on.
Hair Decorations - Of the three important females, the Cute Clumsy Girl is the one with the little hairclips.
Everybody Did It - All three suspects are Batwoman.
Expy: Sonia was inspired by and based on Renee Montoya, a character created for the animated series that was adapted into the comic continuity.
Fake Static - Shame on you, Bruce.
Gender Blender Nickname - Roxanne "Rocky" Ballantine.
Hot Scientist: Rocky
Interquel - Between Batman the Animated Series and Batman Beyond. Many features of the Beyond batsuit are taken from Batwoman's and it sets up the Bruce/Barbara relationship mentioned in the latter series. Tim Drake is still Robin and visibly older than his appearance in The New Batman Adventures, but it is before the Flash Back scenes in Batman Beyond: Return of the Joker.
- Oddly enought he looks younger in the flashback than he does here.
Kick Chick - Batwoman's fighting style.
Let's You and Him Fight - Played with. Batman is out to stop the reckless Batwoman, but in their first face-to-face encounter he comes to her aid when she is surrounded by Mooks. They later have a scuffle, but there is no real misunderstanding at work - she just does not want Batman to stop her.
Lighter and Softer - As compared to other Batman animated films. In the clearest departure from its roots, more scenes take place in the daytime.
Mafia Princess - Kathy.
Maybe Ever After - Bruce and Kathy at the end.
Missing Mom - Kathy's was killed by hitters after Carlton Duquesne.
Morph Weapon - Batwoman's shape metal restraint.
Mythology Gag - I think we've got enough bat freaks in Gotham already, I mean sheesh, what's next? Bathound?
Ninja Maid: The penguins club staff
No Dialogue Episode: "Chase Me", a short included on the DVD.
Not That There's Anything Wrong with That: When Roxanne accidentally misspoke about Bruce's playboy reputation concerning women during one of her ramblings.
Non Indicative Title - It's actually "Mystery of the Batwomen".
Omnidisciplinary Scientist: Batwoman is a brilliant martial artist who also invented miraculous gadgets and is a skilled and experienced computer hacker. It turns out it is three different women using one costume who each bring their own skills to the table.
The Other Darrin: David Ogden Stiers replaced Paul Williams as the Penguin and Hector Elizondo replaced Henry Silva as Bane.
She Is Not My Girlfriend: Bruce acts this way when Barbara calls him on the phone.

Barbara: But... spring break will be coming up soon and I'll be back in Gotham for two whole weeks. (*suggestively*) Won't that be nice.
Bruce: ... Yes. We'll all be happy to see you.
Tim: Don't drag me into this.

Shout-Out - The original Batwoman, Kathy Kane, is referenced by the identity of one of the women potentially behind the mask: Kathy Duquesne.
Scary Black Man - Carlton Duquesne, Kathy's father.
Sophisticated As Hell:

Alfred: As they say on the streets 'I aint touching that one'

Stealth Hi Bye - Par for the Batman course.
Suspiciously Similar Song - the song at the end to Shakira's hit "Whenever Wherever".
The Three Faces of Eve - Rocky (Innocent), Sonia (Capable), Kathy (Sexy).
The Unfettered - Batwoman has no Thou Shalt Not Kill proscription, and will use guns. Sonia references this at the end, when she asks Batman how he manages to still see the line when he puts on the mask, since she, at least, has trouble with it.
You ALL Share My Story - Rocky, Sonia, and Kathy all have a beef either with a Bat-villain, or Carlton Duquesne. More indirectly, each shares a trait with Batman: Rocky his intelligence, Kathy his wealth, and Sonia his determination.