Catch Phrase: "I'm sorry!" (Usually when he's being scolded by Chiaia.)
Chaste Hero: He shows some signs of it, but we can't blame him; he just wants to go home.
Chekhov's Gun: Prior to him being sent to Geminar, Kenshi was hypnotized by Washu to ensure no one knows they have a spaceship (or any of their outer-space Magitek in that matter). This becomes important in the last episode when Chiaia promises to let him dig all the crystals he wants if he beats Gaia, causing him to form a Light-Hawk BFS and break through Gaia's impregnable armor.
The Messiah: It's shown and discussed several times in the series that his influence catalyzes those around him into becoming better people and True Companions.
Mistreatment-Induced Betrayal: 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.
Mundane Made Awesome: Kenishi uses 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.
My Master, Right or Wrong: When he's first captured by Lashara, Kenshi plays dumb about his bosses out of honor. Fortunately, he figures out that his loyalty wasn't reciprocated.
Nature Hero: Even the elves are impressed by how well he knows his way in the forest.
Wrong recipe. Rea (Kenshi's mother), has been said to belong to the Masaki clan from the very beggining, meaning she is part Juraian. The most sensible theory, given the time between the end of the previous civilization and the main timeline is that the third doll married a son of Katsuhito/Yōshō and became Kenji's ancestor (given the average lifespan of a Juraian, it could very well have been Rea's mother or grandmother).
Ms Vice Girl: She eagerly takes advantage of all the money and status she can get (especially what she can get because of Kenshi), but from the moment she spares Kenshi she shows a deep compassion for both him and Chiaia.
Verbal Tic: In episode 3 when training Kenshi for his job as a masseuse, she starts ending her sentences with "zamatsu" (translated in Funimation's subtitled streams as "Don't you know?" and in the English dub as "Baby Boy/Girl".). She still says it on rare occasions.
Animal Motifs: Her Seikishi outfit features a butterfly on her back. Her Seikijin also has a moth motif.
Big Damn Heroes: Shows up in the nick of time to prevent the Meteor Fall (which was hijacked by Cordyline and the bandits) from destroying the Swan in episode 10, giving Kenshi a chance to take out one of the reactors that was keeping it afloat.
Crush Blush: Practically every time she looks at Kenshi.
Cry Cute: In episode 6 after finding out that her bare breasts are pressing against Kenshi's chest (after being disrobed and pushed by Flora, no less), requiring both Lashara and Maria to comfort her afterwards. D'aww...
Mad Scientist: She has a tendency to make excuses to use her inventions to solve her problems (When you have a giant robot, everything starts looking like a nail). Kenshi in particular inspired many improvements to her Mechaworkers by being a guinea pig for previous versions.
Older Than They Look: Her actual age is 97 due to her being in hibernation at the Barrier Workshop prior to the series.
Reed Richards Is Useless: Averted — The Mechaworkers changed the face of warfare on Geminar, especially after Emera stole the plans.
Not So Stoic: Notably during her weak period. She does display a surprising amount of emotion for an Elf though, given her father is of the extremely rare (for Elves) hot blooded variety...
Weaksauce Weakness: Like all of her people, once a day for about an hour Aura loses most of her physical strength while her personality changes to something befitting a Distressed Damsel (This gets used as an excuse for some Rescue RomanceShip Tease with Kenshi, and a few laughs when she returns to normal).
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.
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.
Morality Pet: Episode 6 establishes its characters' moral bona-fides by their reaction to him trying to meet with Hazuki. Kenshi agrees to keep quiet as soon as he hears, tries to arrange for the pair to escape together, and asks his harem to do the same. The haremettes agree, with various degrees of reluctance, because of Kenshi. Dagmyer, who overheard Ceres explaining to Kenshi, dismisses him as a wuss for not taking what he wants, but keeps quiet. On the other hand, Cordyline is introduced helping smuggle Ceres to his rendezvous, but reveals that she's planning to kidnap and sell him.
Star-Crossed Lovers: Again, with Hazuki, because of his status as a Sacred Mechamaster. This later becomes defied upon joining the Swan (now under Kwnshi's leadership).
Even Evil Has Standards: In episode 11 where he accepted Cliff's heinous plan to lure in (and eventually kill) Kenshi using Ceres as bait with a dangerous reactor strapped to the back of his Seikijin. He showed some disgust in the plan, but hesitantly accepted in hopes of it succeeding, even if it means having to kill another Seikishi.
Unlucky Childhood Friend: To Chiaia — although she's attracted to him, the rules forbidding male and female Seikishi dating freely kept them apart (Ultimately, the problem was Dagmyer's inferiority complex).
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: His 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.
Well-Intentioned Extremist: Dagmyer wants to change the status quo because he's sick of being treated like a stud horse. Too bad he's doing this by following Babalun's orders.
Voluntary Shapeshifting: After Mexiah's personailty merged with her, she has the ability to freely shift between her and her Mexiah persona.
What Is This Feeling?: Asks herself this in episode 8 upon realizing that some remnants of Mexiah's personality are keeping her from killing Kenshi. This later becomes subverted after discovering that he is an artificial human like her.
Mommy's Little Villain: Lan eagerly follows in her mother's footsteps. Even carrying on without blinking when Cordyline is killed fits.
Dangerously Genre Savvy: In episode 11 when the Seikishi of the Swan were busy forming Kenshi's BFS out of a compressed mountain. Instead of attacking them at their full health, knowing she and the other bandits will get curb-stomped, Lan simply waits until they are exhausted and reach their operational limits. And she nearly succeeded had it not been for the Holy Land Academy's intervention at the last moment.
Crouching Moron, Hidden Badass: Not only can she switch from a ditzy hedonist to a formidable political leader (and back) in seconds, she's an old Seikishi ace who's able to pilot a Mechaworker like a pro the first time she gets to see a prototype (to Wahan's shock).