Not to be confused with Princess Mononoke, the Miyazaki film.A spin-off of the third installment of the horror anime Ayakashi Samurai Horror Tales. Unlike its predecessor, these mononoke have merged with the powerful emotions of humans, making them even more dangerous and hard to combat.The story follows the mysterious, nameless medicine peddler in his travels and the various people — and monsters — he ends up encountering. To slay the mononoke he must find the Shape (true form), Truth (origin), and Reason (what it hopes to accomplish) in order to defeat it. The series is divided into five story arcs.The style of the anime is done in the Unmoving Plaid style of Gankutsuou (although to a lesser extent—there are actually some solid colors here and there, for example), and though it may take some getting used to, the way the series utilizes it is absolutely chilling in certain cases.
Brother-Sister Incest: A major motivation for Genkei, and was the reason for the creation of the mononoke in the Umi-Bozu arc.
Call Back: A girl that worked for the family haunted by the bakeneko in Ayakashi is a main character in the Umi-Bozu arc. What seem to be reincarnations of her and that entire family also show up in the last arc, mainly for the purpose of planting Epileptic Trees.
Catch Phrase: "Tada no kusuriuri desu yo," or "I'm just a simple medicine peddler."
Cats Are Mean: Very much averted. Cats are sweet, innocent creatures who only want to help, and even Bakeneko only become what they are because of human cruelty.
Celibate Hero: For all intents and purposes, the Medicine Peddler appears to be happily married... to his 'job'.
Closed Circle: About once an episode, often due to the Medicine Peddler closing off all the exits to prevent the mononoke attacking and/or escaping. Additionally, the Umi-Bozu arc is set on a boat and the Bakeneko arc in a train carriage.
Deadpan Snarker: The Medicine Peddler is shown to possess a brutally dry wit, especially when it concerns people who annoy him or get in his way (like the idiotic samurai from the original Bakeneko arc).
Flying Dutchman / Walking the Earth: The Medicine Peddler's purpose is to wander the earth eternally, exorcising mononoke; but it's quite difficult to figure out whether he does this out of choice or whether he has been forced to do so and is taking it really well.
In fact, the series ends with an arc set in the 1920s, whereas the other arcs take place during slightly different time periods from before the Meiji restoration.
I Know Your True Name: The mononoke's "katachi" (which can mean 'name' or 'form') is one of three factors that must be known to the Medicine Peddler before he can draw the Sword of Exorcism.
Implausible Hair Color: The Medicine Peddler, Genkei (even though his sister has black hair like any other Japanese), Shino from the Zashiki-Warashi arc... not to mention some characters who look like they're of African descent, complete with afros to match.
Inexplicably Awesome: Kusuriuri. We have no idea who he is, where he comes from or how he got his powers, only that he kicks mononoke butt for a living and looks fabulous while doing it.
It Can't Be Helped: In the first episode, the elderly innkeeper gets tired of arguing with the pregnant foreigner over how there's no room in the inn. She just gives up, says it can't be helped, and lets her sleep in the abandoned room in the attic.
Jidai Geki: Though it frequently jumps throughout different eras.
Jump Cut: Used deliberately and frequently, the better to increase viewer confusion.
Literal Split Personality: Or something along those lines. It's implied that the Medicine Peddler's normal and demon-slaying personas are two separate entities who switch places as necessary, and at one point the normal persona passes the demon-slayer a mirror to shield himself with.
Malaproper: The Medicine Peddler ends up mangling a Japanese idiom (or to be exact, mixing two idioms together) regarding fish, in the Noppera-Bo arc.
Marked Change: When the Medicine Peddler switches into mononoke-slayer mode.
Mask Power: The Fox-Man in the Noppera-Bo arc, though it's implied that he was really an illusion created by the Medicine Peddler to help free Chou. Maybe. Masks also play an important symbolic role throughout the arc.
Mukokuseki: Mostly averted, with the obvious exception of the Medicine Peddler. However, Shino and Genkei both have blond hair and blue eyes; Genkei's pass without comment, but the innkeeper's servant seems shocked to see Shino's hair color after she removes her head scarf, suggesting that she might really be a foreigner. There's also the fact that said inn is run by two black people...
Older Than They Look / Really 700 Years Old: It's implied the main character has been around a long time. Even in the Bakeneko arc, set about 200 years later than the others, he still retains his youthful looks.
The Rashomon: Absolutely no one tells the truth the first time they're asked for their story. A lot of the time they pay for it, too.
Red String of Fate: A variation involving a red cloth between and unborn child and their parents. A much more traditional example appears in the OP, with a red string tied to the pinky finger.
Reincarnation: Implied. The mononoke in the final arc (episodes 10-12) is a bakeneko, and the characters seem to be reincarnations of the people from the original Ayakashi arc (where the enemy was also a bakeneko). Funny the little coincidences, eh?
Rule of Three: The Medicine Peddler needs the mononoke's Shape (形 katachi), Truth (誠 makoto), and Reason (理 kotowari) in order to purify it.
Scenery Porn: Oh hell, is there ever! The scenery is so rich, detailed and colourful it's like going on a (very beautiful) acid trip.
Ship Tease: Carrying over from the original Bakeneko story, Kayo gets some with the Medicine Peddler - while she's obviously attracted to him and he treats her more kindly than he does others, he still finds time to tease her (and the viewers).
Shout Out: The painting on the boat in the Umi-Bozu arc is reminiscent of the 1907 artwork "The Kiss" by Klimt.
"Silly Me" Gesture: The Medicine Peddler in the ninth episode with plenty of sarcasm, when he 'realizes' that he's given poisonous oleander to one of the characters.
Situational Sword: Why exactly it needs to empathise with the mononoke before slaying it is never explained.
Time Skip: The Bakeneko arc takes place in the 1920s while the rest appears to be set in the Edo Period, but the Medicine Peddler himself hasn't changed at all (besides having some new jewelery). There are arguably small hints in each arc that time skips forward about 50 years in between each of them.
Particularly in the Bakeneko arc, when in addition to being a guy with pointy ears and red markings all over his face in the middle of a Japanese cast, he's also dressed a good 100 years out of date. (Even in the other arcs, his manner of dress is pretty bizarre even for the time, mixing male and female styles liberally.)
It also uses aristocratic materials and styles, despite his humble profession; something that nobody ever comments on. But in the Bakeneko arc he at least explains that people who seek folk remedies expect their seller to look exotic.
His clothing design and style actually seems very familiar to the traditional wear of the Ainu, an indigenous Japanese race. Some of his facial markings also appear akin to the Ainu.
White-Haired Pretty Boy: The Medicine Peddler's other form, who in a way manages to be even more attractive than his normal one. Except for the black teeth, at least.
Those may be justified; there was a historical custom in Japan during the Edo era called ohaguro (link goes to the Other Wiki) in which the teeth were ornamentally coloured black. Mostly done by women, but men did colour their teeth on occasion. (In fact, teeth that were lacquered black were seen as quite attractive.) There's even conventions that combine ohaguro and noh mask-like makeup...
Woobie, Destroyer of Worlds: The "regret" of some of the mononoke could make them this, especially the Bakeneko in both the manga and the final arc of the anime, as well as the Noppera-Bo. The Medicine Peddler even ends up apologizing to the mononoke before slaying it in the manga arc.
Workaholic: It's even implied in episode 4 that should the Medicine Peddler be unable to exorcise a mononoke (or conversely, should all mononoke cease to exist) he'd disappear from this world. So it's quite difficult to figure out whether he's truly devoted to his duty or whether he has no other choice — though going by his frequent displays of enthusiasm and interest in the mononoke and their histories, he seems to be genuinely fond of 'work'.
World of Symbolism: Pretty much the only way to make sense of the series... especially the Noppera-Bo Arc.