Allison and Lillia is a 26-episode, 2008 anime adapted from two related Light Novel series by the same author-illustrator team behind Kino's Journey. The series is set on an alternate world of roughly 1930s-era technology, with one big continent split down the middle by a huge river. As a result, two distinct cultures developed in the East and West, neither of which can seem to get along with the other: there have been countless wars in the past, and the west's Allied Kingdoms of Bezel-Iltoa and the east's Roxcheanuk Confederation are technically only in the middle of an armistice, albeit the longest one to date. (It's not as grim as it sounds.) The origination of the war is that both sides believe their ancestors to be the true ancestors to humanity; apparently, neither one has heard of river valley civilizations. By the "World Calendar" shared by both sides, they are in their 3287th year of recorded history.The story revolves around Teen Genius / Ordinary High-School Student Wilhelm "Wil" Schultz and Genki Girl / Ace Pilot Allison Whittington, two orphaned childhood friends who unwittingly stumble onto a tale of a treasure that could end the war. Complicating matters throughout are Allison's growing feelings for Wil, which, despite his perfect memory and keen observation skills, he completely fails to notice. (It doesn't help that she just can't seem to confess due to the plot continually interrupting her.) Over the course of their travels, they first encounter Carr Benedict, an overly-amorous officer of the Sou Beil Air Force, and Fiona, a young woman in a mountain village who harbors a great secret.A straight-up Adventure with Action and Mystery elements, it avoids (for the most part) the frequent Mind Screwery of the aforementioned Kino's Journey. It is also features continuing plots, rather than the standalone, episodic nature of Kino. This is a blessing and a curse, with the upshot that the producers of the anime were faced with the unenviable task of cramming 10 books into a single 26-episode series. The series retains a certain charm that makes it hard to resist, with an opening theme that sets the tone perfectly. (See here.)
Allison and Lillia provides examples of the following tropes:
Accidental Hero: Benedict agrees to take sole credit for the discovery of the "treasure" sought by Allison and Wil. He soon regrets this, however.
Anime Hair: Averted, with characters sporting realistic hair colors and styles. Black hair does tend to get a purplish cast in illustrations for the sake of contrast though, which can lead to confusion.
Arc Words: Mr. Terror, the steel magnate, is name-dropped in each of the first two Allison stories, but exactly who he is or what he has to do with these plots isn't discussed until the third arc, when he finally shows up in person.
Author Appeal: Keiichi Sigsawa appears obsessed with minutiae of all sorts of technology, judging by the overly-detailed descriptions of all weapons and vehicles that appear, plot-centric or not. Even his pen name is based on a gun brand.
Bilingual Bonus: Disappointingly averted in the anime. While the alphabet used in this world can be deciphered, all it reveals is badly romanized Japanese and poorly translated English.
Book Ends: The second Allison novel is framed at the beginning and end by letters between Wil and Allison. Similarly, the third book begins and ends with a 15-year-old Lillia; what she reveals about her father in the prologue sets up one of the major dramatic themes for the book, while the epilogue shows what really happened to him. The anime uses these bits in episodes 13 and 14, while directly showing the audience what happened before it gets there.
Cassandra Truth: At the end of the first book, Wil tells his friend what really happened when he and Allison went missing for several days. The friend doesn't believe it, thinking Wil is just trying to avoid sharing the scandalous details of their abscondment.
This probably also qualifies as a Paper-Thin Disguise, considering all he did was dye his hair...
Chekhov's Gun: A variety of things introduced earlier in each arc come together to play a part in the end of the story. The anime sometimes forgets to introduce them before they become necessary, however, which turns them into something of a different nature.
At the time, he really skirts the line between being this and a Handsome Lech; by the adventure in Ikstova, however, he's matured into an Officer and a Gentleman (though less by choice and more due to the fact that all women now fawn over him).
Climbing Climax: The villain of episode 8 is made quite Genre Blind in order to accommodate the changes to the climax of the Ikstova arc. On the bright side, he gets to store knives in Hammerspace...
Cool Guns: The author's fascination with firearms on display in Kino's Journey is evident here as well. However, it takes a backseat to...
Cool Plane: Classic propeller-driven aircraft drawn from history.
Cool Train: Murder plot aside, who wouldn't want to ride cross-continent on the ultimate of luxury trains?
Family-Unfriendly Death: In the first and second books, respectively, Walter MacMillan and Owen Nikhto commit suicide. Wil also shoots two people: three if you count helping Allison aim and fails to kill one only because he's not aiming to. In the third book, Colonel Aikashia kills a number of people, presumably while they are asleep. In all instances, these are toned down for the anime, though the last one also has the individual taking out some soldier-types instead.
Genki Girl: Allison, as well as her daughter Lillia.
Hyper Awareness: Wil has this skill towards everything except Allison's feelings. It helps him sort out pretty much every unresolved plot strand in one fell swoop at the end of each arc.
The anime often forgets to give opportunities for the audience to catch these clues, however, making his deductions appear to come from thin air.
Improbable Age: When introduced, Wil and Allison are 17, Benedict is 24, and Fiona is 20. The anime never explicitly states this, however, and between the characters' appearances and certain creative casting decisions, one gets the impression that they're quite a bit younger.
Info Dump: Justified through the conceit of students receiving supplementary instruction on history and geography in the first book / episode, and Wil getting his friend up to speed on Ikstova in Allison II. Lampshaded in episode 14 of the anime, when Lillia complains to Treize about his reading the Rachika tourist guidebook aloud.
Karma Houdini: Colonel Aikashia makes a living of "neutralizing" threats to peace, along with any bystanders that happen to get in the way. Yet, in spite of all the duplicity and the body count he incurs in his first appearance, all is forgiven once it's revealed that he's Allison's father.
King Incognito: Subverted twice: Fiona is actually impersonating her twin sister to fulfill her dying request, while among the main cast, only Lillia is unaware that Treize is royalty.
Plot-Based Photograph Obfuscation: All photographs of Allison's father mysteriously disappeared after his death; this happens again after the Time Skip, where the only photo remaining of Lillia's father is the one where he moved, blurring his face.
Poirot Speak: Benedict, in the second novel. He has some trouble with verb tenses and subtle nuance in Roxchean, which he corrects... and then goes back to speaking Bezelese.
Since both languages are rendered as Japanese, however, there's no insertion of random words from his native tongue.
Precursors: The ancient humans who gave rise to both East and West, but were themselves from the very middle, near the confluence of the Lutoni River.
Runaway Train: Sort of: the train itself is never out of control, but for all the things that happen on it, it might as well be.
Scenery Porn: Perhaps slightly less obvious in the anime, but the author enjoys giving the plot interesting surroundings to happen in.
Selective Obliviousness: Wil never forgets and never misses a detail, no matter how small. Except, of course, when it comes to Allison.
Shoot the Dog: It seems intelligence agents have no qualms about offing innocents, as long as it prevents another global war.
Sickeningly Sweethearts: The daughter of Benedict and Fiona is not amused at her parents' tendency to make out in front of her.
Spin-Off: Meg & Seron, featuring two of Lillia's classmates, which Genre Shifts the series into High School comedy territory. Consists of 7 books. The sequel novel Story of a Single Continent folds their antics back into the main series, with the book's sub-title being Allison & Wil & Lillia & Treize & Meg & Seron & etc.
Spin-Offspring: Not so much a spin-off as a continuation, Lillia and Treize stars the children of the original's core quartet. The main cast of the Allison books are still there, too.
Traintop Battle: Averted when the individual Allison tries to go after tricks her into ducking long enough to escape.
Translation Convention: Roxche and Sou Beil each speak a different language, both of which are rendered as Japanese for the readers' convenience.
The anime seems to discard this entirely, perhaps because this would be unnecessarily confusing (if more realistic). If nothing else, having to interpret every other line is tedious and eats up screen time.
Translator Microbes: Personified in Allison and Wil, who are fluent in both languages and serve as the justification for them being equally understandable to the audience.
The books also play with this trope a bit: in plot-relevant situations, the narrative sometimes gives critical information that only parties who speak the same language can understand. Wil frequently plays the role of interpreter, especially in the presence of Fiona (alone among the main cast in not understanding Bezelese.
In the first book, this is how the two of them get the location of the treasure from Walter without the guard being any the wiser. In the third book Major Stork reacts to statements before Wil has had a chance to translate them, hinting at his true nature.
Weird Moon: The Moon is much closer to the Earth than in our world, orbiting every 8 days and causing spectacular solar eclipses with frightening regularity. Though for some reason, calendar months are still around 30 days long...