The 2009 anime Isekai no Seikishi Monogatari (Tenchi Muyo: War on Geminar in the States) is a Canon spinoff of the Tenchi Muyo!OVA series that takes place 15 years after Tenchi Muyo GXP. The main character, Tenchi's half brother Kenshi, is forcefully taken from his home and his family by unknown forces, and sent to a new alternate universe on a planet called Geminar. There are a few thinly veiled references and nods to the Tenchi Muyo series while Omake material released in Manga, Novel and Doujinshi formats expands the series and further fleshes out the overall story (something Masaki Kajishima has a reputation for).At the beginning of the show, Kenshi has been told he needs to help with an assassination plot in return for going home. The target of assassination is the newly crowned queen of one of the lands in this world. When faced with killing a girl roughly the same age as him he can't do it. Eventually, he ends up being a servant of the queen while she is attending a super elite school for nobility and pilots for somewhat organic looking super robots. Being the little brother of the guy who pretty much made the Harem Genre what it is today, it doesn't take long before the good ole Masaki charm goes to work and gets chased by almost every girl in the school.....literally.The show was released in OVA format (one episode a month), but also aired on television through Japanese pay-per-view service. The first episode was later "enhanced" with extra scenes for the Blu-Ray release. FUNimation licensed the series and released a dub in 2013.Now with a character sheet that Needs Wiki Magic Love.
The show provides examples of the following tropes:
Absurdly Powerful Student Council: Justified due to the fact that many world leaders' children go to this school. One episode they elect Kenshi to the school government just so that everyone's attention will be on him and they can actually get work done.
All Amazons Want Hercules: As the series progresses Kenshi's harem keeps getting bigger until it pretty much includes everyone at the school. Keep in mind that the attendants at the school include the kids of all the top leaders of the world's governments.
Almighty Janitor: Before Kenshi reveals that he's a Seikishi, he manages to earn this kind of reputation as Lashara's servant.
Given that Kenshi acts like a male version of Ryo-Ohki much of the time.
Background Magic Field: The "Draft of Ena", which supplies power to the Seikijin mecha and most of the Magitek in the series. It only extends to a certain height, so some areas, like the highlands, are off-limits without special equipment.
Berserk Button: Kenshi loves his crystals. Chiaia can make him do almost anything if she threatens his collection. On the other hand, Kenshi only forms the Light Hawk Sword in the final battle when she promises to let him dig all he wants if he beats Gaia.
Beta Couple: Ceres and his girlfriend Hazuki, once they join the crew of the Swan.
Also, the students at the Holy Academy spend so much time acting like... schoolgirls, it's easy to forget that, say, Lapis is a fully-trained Action Girl who knows how to use a Humongous Mecha.
Big Bad: Babalun who is being controlled by the core crystal of the Seikishin Gaia that was implanted in him at a young age. Gaia itself is The Man Behind the Man scheming to revive itself.
Big Damn Those Four Girls: In episode 12, when Lan attacks Kenshi's group while they're creating the Tenchi-Ken; they arrive in the nick of time, giving Kenshi enough time to finish the sword and save the day.
Bi the Way: Mexiah might be one if episode 8 has anything to say about it.
BFS: Some of the Seikijin wield these. In episode 12 Kenshi compresses a mountain to create a huge stone BFS. Which turns into an even biggerLaser Sword in the final episode. Which then turns into a smaller but far more powerful Light Hawk Sword.
Bloodless Carnage: You can rip a Sekishi in pieces, but you never see anything else really bleed.
Cast as a Mask: Used as a Red Herring when Mexiah had the same voice actress as the mysterious masked woman Neizai who tended to show up when Mexiah disappeared. Mexiah was actually the alter ego of Doll (different actress), and Neizai was actually Rea Second (different actress). The show actually throws a red herring in the Wham Episode, when Ulyte talks to Neizai while the camera shows a closeup of Mexiah with Mind-Control Eyes... with her mouth conveniently obscured.
Character Development: The first half of the series is devoted to this (and Fanservice). Initially Kenshi just wants to go home. While he never really loses that goal, he also grows closer to his fellow students at the academy including the members of his Unwanted Harem. All so that by the time the series gets back to the mecha action, Kenshi actually has a reason to fight other than "I want to go home".
Char Clone: Dagmyer. Masked blond, inspiring leader and idealist, Manipulative Bastard... he hits most of the criteria except that he uses a blue Seikishin. And that he's hopelessly outmatched by Kenshi.
Due to cooking skills, strength/speed, and all around niceness. The fact that male Seikijin pilots are already in high demand around here doesn't hurt, either.
Clingy Jealous Girl: Lashara when she actually sees affection that might get Kenshi from under her thumb (especially involving her Rival). Chiaia whenever Kenshi appears too happy. Both whenever there's something to blame or exploit.
Color-Coded Characters: The various Seikijin have colors and outward appearances dependent on who is piloting them.
Colourful Theme Naming: Those Four Girls have names loosely based on their hair colors — Yeliss, Bwoole, Gryino, and Wreda. Their Seikijin is even the same color as their hair color, taking this trope Up to Eleven.
Conveniently Unverifiable Cover Story: Lashara and Chiaia decide to hide Kenshi's connection to the white Seikijin that attacked the Swan in the first episode by having him serve as one of Lashara's servants. Instead of revealing he's from another dimension (which would basically ruin the deception by itself), Kenshi hides his unfamiliarity with the customs of the world of Geminar by claiming to be from "Kouchi" — the highlands (Kouchi actualy means this) above the Draft of Ena which powers the Seikijin and the other Magitek, and whose residents are conveniently isolated socially as well as physically.
Cooking Duel: A literal example breaks out in the fifth episode when Maria tries to set a Honey Trap for Kenshi; Aura suggests that everyone gathers ingredients in the forest and cook a pot-dish with them. The best dish wins ownership of Kenshi.
Darwinist Desire: It is revealed that due to male Mecha Masters being so rare, they are made to marry female Mecha Masters to produce superior Mecha Masters. Kenchi even compares male Mecha Masters treatment as if they were breeding horses and the sperm of a male Mecha Master is very valuable. Women Mecha Masters on the other hand are free to marry whoever they want since there is so many of them.
Double Standard: Abuse, Female on Male: Several members of his harem but in particular: Chiaia, whenever he appears happy, quota demands it, or just when she's bored or something good happens to him. Lashara and Mexiah whenever there's an opportunity to exploit him for their own gain or to make him unhappy, and Lithia who refuses to acknowledge him, and frequently puts him down (much like the others in this list).
Dub Name Change: In Funimation's subtitled streams, they changed "Seikishi (Holy Machine Wielders)" to "Sacred Mechamaster", "Seikijin (Holy Machine Men)" to "Sacred Mechanoid", "Seieishi (Holy Defenders)" to "Sacred Mechaguardian", "Seikishin (Holy Machine God)" to "Sacred Mechalord", and "Kikkoujin (Machine Workers)" to "Mechaworker".
Faux Action Girl: Lan comes across as a Faux Dark Action Girl. More generally, the trope gets inverted here: most Seikishi (pilots) are female, and the few male pilots are coddled, condescended to, given substandard training, and treated like "stud horses". Dagmyer's rebellion is partially a Jackie Robinson Story, trying to prove that male Seikishi can hold their own on the battlefield — but after a promising start, they get shoved to the sidelines and outshone by the women on Babalun's side (Kenshi and Aura's father are full-fledged Action Guys, though).
Fetish-Fuel Future: Some of the previous otherworlders brought to Geminar made their marks on the culture — like the pillow fight in episode six. Kenshi's disturbed about how much of it he recognizes from his father's "library".
Hour of Power: Pilots can only operate Seikijin for limited amounts of time.
Humongous Mecha: The Seikijin. Prominent in episode one, then all but ignored until episode 8.
I Didnt Mean to Turn You On: Kenshi is a rather bizarre case. In episode 3, Mexiah somehow brainwashes him to make him turn into a "berserker massage machine" at her command. Then she gets Wahan, Aura, Lithia, Yukine, and various other girls to help him practice without getting into the specifics. Afterwards, all of them are left in states of heightened arousal and sensitivity; in Yukine's case, just being lightly tapped on the back nearly triggered an orgasm.
In episode 6, Lashara and Maria trigger his "massage machine" state again to get payback from Queen Flora for their earlier humiliations in that episode — knowing only that Kenshi's massages leave girls "paralyzed", and not the nature of said "paralysis". This backfires on them; they are forced to stay up all night to make sure Flora didn't take things any further, and from that moment on Flora has an interest in poor Kenshi.
If It's You, It's Okay: The girls like Kenshi so much they are willing to let him wash their backs, as in the hot springs bath.
This is a borderline example, since Kenshi did throw Cliff off a cliff. However, since it was Cliff's scheme that sent Kenshi into Unstoppable Rage in the first place it still fits.
Kid Hero: Kenshi is 15, but looks and acts young enough to qualify.
Killed Off for Real: Cordyline in episode 10. Her daughter follows suit in the last episode by Emera.
Know When to Fold 'Em: Dagmyer's cronies (well, except Cliff) finally drop any pretense of loyalty to Babalun roughly at the start of the final episode, and only wait for the good moment to surrender, snarking all the time.
Mental Fusion: Doll's mind essentially merges with Mexiah's in the aftermath of episode 8. Neizai/Reia implies that this is what happened to her and Ulyte after his "death" in the final episode.
Mistreatment-Induced Betrayal: Kenshi. In the first episode, he starts out serving the "Masked Knight" (Dagmyer) while trying to assassinate Lashara, in the hopes of getting home. Dagmyer tries to force Kenshi to do the dirty work he failed at, insults him at every opportunity, tries to have him killed when he outlived his usefulness, and adds insult to injury by admitting that he'd never intended to help Kenshi return home in the first place. A few minutes later, Dagmyer's offended that Kenshi decided to betray his "benefactor" and fight his way out of danger.
Ms. Fanservice: Mexiah. By far. All the women in the cast have their moments, but Mexiah particularly enjoys driving Kenshi nuts.
Mundane Made Awesome: Kenishi using his Super Strength, speed, and Badassness to do chores around the school. A lot faster than the staff can handle (ex. by the time it took a maid to finish half her room cleanings, he finished the same number and came to help her). And that mosaic on the arc. While the three artisans are discussing how to replicate the original mosaic on one tower, Kenshi was already done.
Mythology Gag: Kenshi's constant musings about his older sisters, who are obviously Tenchi's harem. None of them have shown up in the show yet, except for a silhouette of Washuu hypnotizing Kenshi. In addition, Kenshi behaves like Ryo-Ohki when upset, and has a shard of crystal from Ryo-Ohki in a necklace. Doll is very similar to D of Parallel Trouble Adventure Dual both in terms of appearance (also shared with Neju of Tenchi Muyo GXP) and origins.
In the last episode, Kenshi transforms his Seikijin's BFS into a giant Light Hawk Sword and cuts through the "invincible" Gaia's Shield like a hot knife through butter.
There are also multiple references to Kajishima's Photon: The Idiot Adventures. The Koros are more realistic versions of the animal mascot from Photon; Lashara's name is a reference to both Photon Earth and Lashara Moon, Flora and Maria share the surname Nanadan with the villain Papacha, and Lithia shares the same last name as the Pochis. Also, Ahou magic was the MacGuffin of the Photon series.
Old Maid: Mexiah can be considered part of this as at her age because she is still not married.
Omniscient Council of Vagueness: The text conversations at the beginning of the first episode and the end of the finale. According to Word of God, they are two of the Goddesses from the OVA continuity (Tsunami, Washu, or Tokimi).
Our Elves Are Better: The Dark Elves of Shurifon such as Aura are physically superior to everyone on the planet — at least until Kenshi appeared. They do possess an Achilles' Heel a period of time in the day when they are incredibly weak, which according to a Mr. Exposition scientist in episode 11 may be because their bodies are still adjusting to life on a planet other than their homeworld. Despite the name, they're textbook Wood Elves, living in harmony with the forest — another thing Aura and Kenshi have in common.
Puppeteer Parasite: Gaia's core crystal became one of these for both Babalun and his father.
Rape as Drama: It's implied that the female Seikishi hunting Ceres at the start of episode 11 "had their way" with him beforehand. Everybody seems to get over it after his girlfriend is rescued, but this seems to be part of what drove Kenshi berserk.
Really 700 Years Old: Mexiah, aka Doll. Also, Wahanly's actual age is 97. Kenshi at one point wonders if Lashara belongs to this trope (she doesn't) because of her mature attitude and his experience with the person whose picture is currently on said trope's page. Really, though, it wouldn't be a Tenchi Muyo! series without this trope in play somehow. To make it clear, Kenshi is at least 18 years junior to his own brother (he's the Rhea and Nobuyuki's son, and they've married only by the end of the third OVA, when Tenchi already graduated), and 82 to his sister!
Red String of Fate: Invoked in episode 4; Chiaia spends the episode trying to weave a (red) cord to replace the chain of Kenshi's pendant (which she broke while scolding him). She's embarrased and horrified when Lashara's Old Retainer tells everyone about this otherworld custom, and immediately tries to make Kenshi give the cord back. A few episodes later (after she gives up on Dagmyer) when she sees the pendant again, she decides she doesn't mind anymore.
Rescue Romance: In a sense — in episode 3 Kenshi gets Lapis her handkerchief back after it's thrown from a cliff. Without ropes. Using a vine to climb down.
Running Gag: Relentless attempts of the older heroines (mainly Mexiah and Flora, but it's not only them) to have their way with Kenshi.
Sequel Hook: Nothing else can be said about the ultra-ambiguous ending. The jewel's still glowing, ends with the antagonists, etc, etc.
Sharing a Body: After Neizai/Rea's core crystal was implanted in Ulyte, they ended up switching forms depending on whose will was stronger. Neizai eventually took full control of their body when Ulyte's strength gave out.
Shotacon: Mexiah's and Flora's interest in 15 year-old Kenshi is a little disturbing at times.
Stalker with a Test Tube: After Kenshi reveals that he's a Seikishi, he starts to run into this trope from the various nations of Geminar (mostly in the form of various factions of his Love Dodecahedron); Lashara's mostly happy at the chance to play middleman.
Super Breeding Program: In order to ensure a strong future generation of future pilots, all of the Seikishi are effectively in one of these; they're required to have children with multiple designated partners before finally being allowed to marry. The male Seikishi have it worse, being treated like "stud horses" before ending up in Bureaucratically Arranged Marriages.
Supreme Chef: Turns out the secret ingredient Kenshi needed to make his soup better was adding dried and powdered bugs.
Tsundere: Lashara (Type B), Chiaia and Lithia (Type A) all fit the bill to some degree.
Unlucky Childhood Friend: Chiaia to Dagmyer; among other factors, the fact that he wasn't allowed to marry for love as a male Seikishi complicated their relationship. It comes to a head in episode 9 when Dagmyer tries to exploit her crush by asking her to kill Kenshi. In a Shout-Out to an incident in the original Tenchi Muyo! OVA, she nearly goes through with it but backs out at the last moment. Even after this she still tries to persuade Dagmyer to change his mind before it's too late. During a very tense situation she ultimately chooses to go with Kenshi to save Lashara instead of staying with Dagmyer. This just causes Dagmyer to resent Kenshi even more.
Villainous Breakdown: Dagmyer has one spanning most of the series due to growing fear and resentment of Kenshi. It culminates in a Freak Out and complete mental collapse in episode 11 after Kenshi goes berserk in his Seikishi, brutally kills one of his comrades, and nearly does the same to Dagmyer, scaring him shitless.
Villainous Valour: Dagmyer's duel with Kenshi in the final episode is made of this trope. He's still hopelessly outmatched, but he faces his fears head-on and meets defeat with honor.