[[caption-width-right:320:Natsuki, Kotono and Misaki]]

Kotono Hayama is a young girl who lives with Joshua in a church. She and her best friend/admirer, the wealthy Natsuki Shirafuji, help out at the Kuroki Detective Agency. Their story begins with children being kidnapped, with a certain boy, Ewan, being the culprit. Kotono befriends him, and he bestows upon her the power to transform into a MagicalGirl.

As it turns out, the Reverse Corporation, a nefarious group of tarot card users, has been scouting out Arcana City to find Ewan for their boss, President Kurtz. Kotono, Natsuki, and a strange newcomer named Misaki Hijiri form the Goth Loli Detective Agency to solve the city's problems as Black Loli, White Loli and Red Loli.

'''''Saint October''''' was an AnimeFirst series by Konami, airing for 26 episodes from January to June of 2007.

* Note: all uses of the word "loli" within this series and its trope examples on this page are in the sense of ElegantGothicLolita, not the [[LoliconAndShotacon other]] meaning.

!!Tropes in ''Saint October'' include:

* AccidentalMisnaming: When Suzukichi and Osuzu deliver a tape with a warning message to Kotono and company from Esmeralda, none of them can remember her name. [[TheTapeKnewYouWouldSayThat She's accounted for this.]]
* AlmightyJanitor: Eddie Tsukahara, Reverse's janitor, is able to repair Kotono's broken Justice card with no ill effects. [[spoiler: He's Ewan's and Kurz's father and also heavily implied to be god.]]
* AnimeChineseGirl: Seiran, an early villainness with [[BlowYouAway wind powers]].
* AvengingTheVillain: Esmeralda is Herlock's kid sister, set to get revenge on Kotono for killing him.
* BearsAreBadNews: Played straight with a bear that attacks Kotono and Ryouhei on their camping trip, but it turns into an AndroclesLion for Misaki. She befriends the bear and names him Hiroshi Piroshiki Romanov. He even becomes her mount!
* BrainwashedAndCrazy: [[spoiler:Almost all of Arcana City in the finale. Including Joshua.]]
* BunnyEarsLawyer: President Kurtz is a bit of a weirdo. He experiments with random things in his office, seemingly unfazed by anything. But when he gets mad, he gets LaughingMad.
* BulletProofVest: [[spoiler: Worn by a *bear*]]
* ButtMonkey: Koshiro Kuroki, the (former) owner of the detective agency. He is useful a few times, but is generally on the recieving end of bad luck and punishment.
* ByThePowerOfGrayskull: The three Goth Loli Detectives have long, elaborate phrases when they transform.
* CatchPhrase: Whenever Misaki is called "Misaki-chan", she responds with "Don't call me '-chan'."
* CannibalismSuperpower: [[spoiler:Kurtz ''eats'' Ewan in slate form to gain his power and become king of the world.]]
* ConvectionSchmonvection: Averted; when Kurololi hangs over liquid iron, she faints from the heat alone.
* DeliberatelyCuteChild: Esemeralda
* {{Dissimile}}: One Enemy of Kotono's reasons of staying loyal to the Reverse Company is they have taken away a (literal) curse of bad luck from him. After he lists some of the things which have been happened to him, she replies with: "It's like a bargain sale of bad luck! Only nobody's buying anything".
* DrillHair: For bonus points, it's even [[{{PrehensileHair}} prehensile]].
* ElegantGothicLolita: They are the Goth Loli Detectives.
* [[spoiler:EverybodyLives]]
* FaceHeelRevolvingDoor: Ryouhei starts off as not affiliated with Reverse at all, joins them, is convinced to turn away, and then rejoins when the mass brainwashing begins.
* FortuneTeller: Artista
* GreenLanternRing: Misaki's arrows are incredibly versatile, transforming into whatever she calls out.
* ImaginaryLoveTriangle: Cecil, a fellow student of Kotono's, thinks she's in love with Ryouhei, and even gets tarot powers to take her down. When it turns out they're not close at all, Cecil ''lets'' Kotono purify her.
* IndecisiveParody: When the show tries to be serious and deliver [[{{WhamEpisode}} Wham]], rest assured a major MoodWhiplash will follow.
* LoveMakesYouCrazy: [[spoiler:Sophia is in love with Kurtz, and suffers for it.]]
* LukeIAmYourFather: [[spoiler:Ash is Kotono's father. Joshua took her in because Ash was a neglectful parent who tried to hurt his own daughter once he got his hands on tarot powers.]]
* MagicalGirl
* MegaTwintails: Esmeralda. [[PrehensileHair She can do a lot with them]]. Including [[HairyHammerspace storing things]].
* MorphicResonance: When Suzukichi and Osuzu transform from sparrows into humans, they're still very visibly sparrowish.
* NonHumanSidekick: Kafka, a familiar of some sort.
* {{Ojou}}: Natsuki.
* PsychopathicManchild: Kurz is an amusing version of this. [[NotSoHarmlessVillain Most of the time]].
* {{Premiseville}}: It's called Arcana City, and there are tarot cards involved.
* SelfParody: Where a lot of the show's humor comes from.
* SpellMyNameWithAnS: Various translations disagree on names like Elrock/Harlock/Herlock and Ewan/Juan.
* SuperEmpowering: Ewan [[spoiler:and Kurtz, being slates]], can give the power of the tarot cards to anyone else.
* TakingTheBullet: H.P. Romanov takes a few arrows for Misaki in episode 25. Her brother did the same thing in her backstory.
* TarotMotifs: All magical powers in the show are drawn from tarot cards. Reverse holds most of them.
* TeamPet: Two. Nike the parakeet and Xupery the cat.
* ThemeNaming: There are two patterns to the girls' names. ''Ko''tono, ''Na''tsuki and ''Mi''saki spell out "Konami". There's also "Hijiri" (聖), the "To" in Kotono (小'''十'''乃) and the "Tsuki" in Natsuki (菜'''月'''), which together spell out 聖十月, the Japanese translation of "Saint October".
* TrademarkFavoriteFood: Cake, for all the Goth Loli Detectives. Joshua makes them a new one every episode.
* TransformationSequence: A little more visceral than the usual magical girl fare. Fruit pulp covers their bodies and transforms them into their outfits.
* TraumaCongaLine: [[spoiler: Kotono's whole life prior to the series, and in the finale.]]
* UndyingLoyalty: Ash lives for Kurtz.
* WeaponOfChoice:
** Swords: Kotono
** FightingWithChucks: Natsuki
** Archer: Misaki.
* WhamEpisode: [[spoiler: In Episode 12 Kotono finds out getting hit with Judgement for a second time averts NonLethalKO]]
* WhamLine: [[spoiler: Did you become so possessed with power that you forgot your own daughter?]]
* VerbalTic: Esmeralda exchanges all "shi"s for "chi", such as calling herself "atachi", and ends every sentence with "de chi".