History Anime / UmiMonogatari

* AnAesop: [[spoiler: Everyone has darkness in their hearts. [[DarkIsNotEvil That's normal]], [[RousseauWasRight and we must learn to accept it, not cast it out.]]]]

* IncorruptiblePurePureness: The Elder Turtle thinks Marin is incorruptible, and strives to protect her from the darkness. [[spoiler:Instead of dealing with her feelings and learning the darkness isn't something to be scared of, she falls into it and ''is'' corrupted, losing her powers as a result.]]

* InnocentFanserviceGirl: Marin's skimpy clothing is commented on when she first comes ashore, though Kanon eventually gets her and Urin to wear something a little less revealing.

* DoesNotLikeShoes: Most underwater citizens, including the two main characters, will go barefoot, unless trying to remain inconspicuous and wearing more conventional clothes of the "sky people."

* BladeOnAStick: The girls are told that to seal Sedna away they must pierce her with the Spear of Light. [[spoiler: It's never seen, as they defeat Sedna and save Urin another way]].

* SurprisinglyGoodForeignLanguage: The shrine maiden's song is sung in the [[http://en.wikipedia.org/wiki/Amami_language Amami]] language, which is on the verge of becoming an extinct language and is officially considered a Japanese dialect.

[[JustForFun/IThoughtItMeant Not to be confused with]] the ''[[{{Lightnovel/Bakemonogatari}} Monogatari]]'' series.

* BareYourMidriff: It's standard for Mermaids, but Oshima and Miyako are prone to this as well.

* MaleGaze: Not to {{Ecchi}} levels, but it is a rare episode that doesn't feature at least one bust or butt being suddenly thrust into the frame.

* WaterIsAir: A ''huge'' offender. Everyone can speak underwater, there's always at least some light no matter how deep they go, there's barely a bubble in sight, defeated characters fall down instead of floating up, people ''cry'' underwater with tears floating away in bubbles, people ''drink tea'' underwater, and everyone's hair hangs down instead of flowing upwards.
* WorldOfBuxom: Downplayed, but pretty much every adult female character except Kanon is at least a C cup.

* EndearinglyDorky: Kanon met Kojima when he got lost trying to find his house after moving in, and he was inititally very shy and awkward around her.

** [spoiler:In the finale, Urin trying to seal Sedna alongside her results in most of her body being turned to stone]].

* ShoutOut: To "Literature/TheLittleMermaid", as [[spoiler: Marin is warned that Urin will turn into sea foam once Sedna is defeated. [[EverybodyLives She doesn't]]]].
** The ending animation has Marin and Urin seeing the story of the Little Mermaid, with Urin crying over it and Marin comforting her.

* IncorruptiblePurePureness: The Elder Turtle thinks Marin is this, and strives to protect her from the darkness. [[spoiler:Instead she falls into it.]]

* PoorCommunicationKills: Kanon never told Kojima she liked him out of fear and naturally assumed he was going to dump her, which made him grow distant from her because he felt she didn't reciprocate his feelings.

* {{Gainaxing}}: Oshima invokes this to get Kojima to notice her, only to be quickly outdone by Marin. It's a more subdued, realistic example than most, however.

* BrattyHalfPint: Urin is this, mainly towards people on land.

** Urin struggles with this to a much greater extent, as she can't fight at all, but wants to very badly. [[spoiler:This desire makes her a wiling host for Sedna]].

Under the sea, two mermaid sisters by the name of Marin and Urin are enjoying their lives. One day, a ring falls from the surface and into Marin's hands. She wants to find the ring's owner and return it, and takes Urin along for the ride. It's then that they run into Kanon Miyamori, a young priestess who's about to get involved in a series of events neither she nor the sisters could've planned for when Urin ends up unleashing Sedna, an evil force intent on shrouding the world in darkness. This is what prompts Marin and Kanon to become the Priestess of the Sea and Sky.

** Kanon struggles with fighting and feels inadequate at times.
** Urin does likewise to a much greater extent, as she can't fight at all, but wants to very badly.

* TheCorruptible: Various sea creatures, but this trope is most present in [[spoiler:Urin]].
* TheCorruption: Sedna's influence, signified by too-bright or red eyes.

* ButterflyOfDeathAndRebirth: Eerie blue butterflies show up the night of the eclipse, and [[spoiler:Urin grows butterfly wings after hatching from a cocoon.]]

* UltimateEvil: Sedna has no real form, and is only seen as shadows and a cloud of red sparkles.

** [[spoiler:Oshima initially seems to be your classic AlphaBitch, but she has ''[[TearJerker heartbreaking]]'' hidden depths. She tells Kanon that even when she was going out with Kojima, all he ever talked about was Kanon. She feels she'll never measure up to Kanon in his eyes, and that it ''hurts'' to like someone that much knowing they'll never feel the same way about you.]]
* MadeOfEvil: [[spoiler:Sedna, though not so much evil as sadness.]]

* WaterIsAir: A ''huge'' offender. Everyone can speak underwater, there's always at least some light no matter how deep they go, there's barely a bubble in sight, defeated characters fall down instead of floating up, people ''cry'' underwater, people ''drink tea'' underwater, and everyone's hair hangs down instead of flowing upwards.

* YouGottaHaveBlueHair: Kanon's hair is a dark blue color, but becomes a lighter tone, when she transforms. Played straight with Warin.

* PhraseCatcher: Marin repeats "I love you!" frequently to everyone she meets, especially early on. In the finale, [[spoiler:Kanon says it back to her as she has to leave]].

* RomanticTwoGirlFriendship: Kanon and Marin become very close friends over the course of the series, but Kanon is in a relationship with Kojima.

* MaleGaze: Not to {{Ecchi}} levels, but it is a rare episode that doesn't feature at least one bust or butt being suddenly thrust into the frame. And of course, the first shot of the opening is a closeup of Marin's ass.

* MoodWhiplash: Setting in from the solar eclipse episode onward. What was once a happy, gentle show takes a turn for the scary.

* MumLooksLikeASister: Miyako, Kanon's mother. She looks young enough to be one of her daughter's friends, and has the personality to match.

* PowerMakesYourHairGrow: Marin and [[spoiler: Urin]] get this when transformed.

* RedEyesTakeWarning: Averted with Kanon and the shrine maiden, but played straight with [[spoiler:a corrupted Urin]].

* SealedEvilInACan: Sedna was sealed away in the sea and on land.
* SealedEvilInASixPack: Sedna; she has half of her in land and half in the sea.

* UnreliableExpositor: The Elder Turtle is completely wrong about a lot of things.

* VolcanicVeins: Those corrupted by Sedna have these, particularly on their legs, arms, and face.

* MaleGaze: Not to {{Ecchi}} levels, but it is a rare episode that doesn't feature at least one bust or butt being suddenly thrust into the frame.