The protagonist, host of Meer, Papi, Centaurea, Sue, and Meroune and guinea pig for the interspecies marriage amendment to the exchange program.
Affectionate Nickname: Meer calls Kimihito "Darling", Papi calls him "Husband", Centaurea calls him "Master" and Meroune calls him "Sir". Ms. Smith calls him "Darling" too because she finds it amusing.
Always Save the Girl: He actually racks up a pretty surprising number of crimes all to protect the girls from random people, the government, and themselves. Assault, lying to the police, harboring an illegal alien, stealing a truck, etc.. He gets away with it because for the most part Ms. Smith just doesn't care.
Beware the Nice Ones: He may be nice, but he won't hesitate to break faces if you mess with the girls under his care.
Blank White Eyes: Pretty much the default setting for his eyes. The only time when you see his actual eyes are when he's shocked or being serious, which occurs more frequently as the story has progressed though still not more often than the blank eyes.
"I haven't seen this in a while. Since chapter 4, I think?"
Crazy-Prepared: When Suu is on her water-absorbing (and orgasm-inducing) rampage in chapter 10 she leaps at Meroune. Kimihito immediately produces a large plastic garbage bag to catch her mid-flight and contain her.
"I really am used to this..."
Crouching Moron, Hidden Badass: Chapter 14 marks the second time he's laid out a grown man with one punch, both brought on by the recipient of said punch antagonizing one of the girls in some way.
Dude, Where's My Reward?: He just barely manages to save Suu's life and Papi calls out to him, flying in like she's going to hug him, and goes right past him to hug Suu.
Got Volunteered: Ms. Smith pretty much just dumped Meer, Papi, Centaurea, and Meroune at his house.
Nice Guy: The driving force behind each of the girls falling in love with him.
Only Sane Man: As is standard with a harem-genre protagonist. Doesn't help that the only authority figure we've seen so far is little better than his harem.
Rescue Romance: So far he has, at least once, ended up rescuing or protecting each member of his harem. Each time either being what caused them to fall for him or, in the event that they already had, to display their affection much more openly.
Kimihito takes an attack from a fake sword meant for Centaurea.
He also takes three tranquilizer bullets in chapter 5, when he jumps in front of the girls.
Kimihito's cultural exchange coordinator. Rather lazy when it comes to her job, yet she still seems to have no problem dumping girls off on Kimihito and using him as a guinea pig for amendments to the exchange program's rules.
Idiot Houdini: Kimihito suffers no end due to her irresponsibility, and she never suffers for it.
This finally backfires on her in chapter 13. She left her coworkers to cover her at work while saying it was to keep the other girls away from Kurusu while ill to avoid a viral mutation, when in fact she just wanted to slack off. Once she catches his cold, her coworkers refuse to help her for the same reason she gave them.
The Lad-ette: She's grossly irresponsible at her job, constantly bums off Kimihito for meals, and her own apartment's a sty.
Ms. Smith: I have a lot of different jobs. Looking for home stays, working as the extra-species exchange ministry's gun...er, as security and surveillance, putting new experiments into practice...but I never get a raise for it. So I'm not gonna deal with this! Illegal entry? New species? Not my job! That's why I won't define "slime" as extra-species!
The hunch was pretty much confirmed with Chapter 11.
Does Not Know Her Own Strength: Meer tends to strangle or constrict Kimihito to the breaking point by accident. Kimihito even reacts to her friendly pats on the back like he's getting punched. And when Lunacy strikes Meer, Papi and Centaurea, all at the same time, they all suffer from this, thus leaving Kimihito facing a very real risk of literally getting killed during intercourse if the temporarily lust-crazed girls manage to capture him long enough to have their way with him.
The Three Faces of Eve: Of the three girls who are in love with Kimihito, Papi is the Child because she is joyous, absent-minded, and a bit naive; Centaurea is the Wife because she is incredibly honorable and chivalrous, as well as unerringly loyal to Kimihito; and Meer is the Seductress because she is very flirtatious, trying to seduce Kimihito on multiple occasions. They do however occasionally take on other aspects.
Meer is a lamia and the first girl that Ms. Smith just dumped off on Kimihito. It didn't take long for her to fall in love with him and has little problem turning on the charm to try to get him to make a move.
Because You Were Nice to Me: The reason she fell in love with Kimihito is that he was the first human she met outside of the exchange program officials/agents (who don't count, as they're probably keep a strictly professional distance), whose first reaction to her was not to shun her for being a monster girl, but to be concerned about her getting cold due to her snake-like physiologynote So much that the first actual thing he does for her on her first day in his house is get her a big blanket to warm up the snake part of her body, because she was obviously discomforted by the air conditioning..
Blatant Lies: Claims that the Homestay Rules clearly state that the first girl to begin their stay at a home has privilege, basically saying she has officially-sanctioned first dibs on Kimihito. Nobody buys it.
Fantastic Arousal: Her tail, specifically the tip. She was also very clearly aroused when Kimihito helped peel her scales off when she was shedding.
First Girl Wins: While nothing has been set in stone, she is the favorite of both the majority of the fanbase and the author, and she's the most open to Darling. Really, it's more that she's built up to be the winner enough that her not winning would seem more contrived.
She invokes this herself to the other guests (see Blatant Lies above).
Hoist by His Own Petard: Drastically lowers the temperature of the room she's currently in to try making Meroune uncomfortable. She's the only one who has any issues with cold. Papi and Centaurea aren't sure if she was going to kill herself or just end up hibernating, but Kimihito fixes the temperature before they can find out.
Hot Blooded: Despite being physically cold-blooded, she's extremely passionate in what she does (i.e. wooing Kimihito). Ms. Smith even mentions it's a trait with lamiae.
Lethal Chef: She's never studied cooking in her life; Kimihito, Papi and Centaurea find this out the hard way when Meer, trying to "teach" herself how to cook (by "emulating" what she saw from Kimihito's own cookwork in the kitchen), tests her culinary creations on Papi and Centaurea, and incapacitates them for an entire chapter! Kimihito initially assumes that the food she made was traditional lamia cuisine and ate it all.
In chapter 13, Mero eats some of her food, and the taste brings to her mind the idea of how it would feel to have her fins torn apart!
Loveable Sex Maniac: She really wants to get into Kimihito's pants. She nearly tried to strip Kimihito while he's sick!
Super Strength: She can crumple steel in her coils with virtually no effort, often without even realizing it. Justified assuming that unlike a snake, all her major organs are probably up in her human half, making her tail a huge mass of solid muscle and bone.
The Tease: It becomes clear very quickly that she doesn't give a crap about the no sex rule of the exchange program as she tries seducing Kimihito fairly regularly.
Tsundere: Type B. She's sugary-sweet to Kimihito, but she can be violent when provoked (especially by romantic competition, i.e. Papi and Centaurea).
It's also dangerous for her to be in large bodies of water for this reason. While she can swim quite well, it's harder to maintain her body temperatures in a pool.
Your Size May Vary: The length of her tail, which varies from being several feet long to closer to twenty feet.
A harpy and the second girl to end up living with Kimihito. She's childish, both physically and mentally, despite being as old as Meer.
Accidental Truth: When she was first introduced she mentioned that she was informed that if she kept flying away she was going to get "deflowered". A few chapters later she, with the help of Meer and Centaurea, runs off with Suu who proceeds to do just that to the three of them.
Adult Fear: She watches the girl she saved early in the series get run over by a truck, who was only saved because Suu managed to wrap her up and absorb the force of the impact. Before they can get Suu unstuck from the side of the bridge they were on, it collapses dropping her into the river and because of her hands not being strong enough to hold people and Suu being slippery she can't do anything but watch her fall.
Big Sister Instinct: She's rather protective of Suu, even flying off with her when the others think about giving her up.
Mama Bear: It's noted that her motherly instincts are really strong. She ends up switching between the two depending on the situation.
The Ditz: Has a short attention span that lasts for mere seconds. The few things she does remember is usually misremembered.
She also tends to focus on completely random minor details. While watching a news report on a hostage situation and how it'll be affecting the Extraspecies Exchange Laws, Meer and Centaurea discuss that. Papi on the other hand.
Papi: "Huh? Isn't that Ms. Smith?... That is Ms. Smith."
Femme Fatalons: Her wings have exposed thumbs like a bat each ending in a sharp black claw.
Winged Humanoid: The "wings-for-forelimbs" variation, but the digits of her wingsnote Yes, birds do have "hands" in their wings in real-life. are somewhat more human finger-like, and thus allow her to hold objects in them, as demonstrated when she was shown holding the Wii Remote in her hand to play with Kimihito's Nintendo Wii. She's not as dexterous with them as humans are with their own hands/fingers, though; she has trouble holding on to an ice cream cone properly, for example.
Adorkable: No, seriously. She has her moments. Just look at her expression when she first holds hands with Kimihito, or giving a Headbutt Thermometer to Kimihito!Suu.
Courtly Love: Since she thinks of herself as a knight, she tends to think of her relationship with Kurusu along these lines: she loves him, but expressing that love or pursuing him would be un-knightly.
Large Ham: Has a habit of being melodramatic. She even compares her meeting with Kimihito to the meeting of Hercules and Chiron.
My Friends... and Zoidberg: Meer draws up a diagram explaining everyone's connections when they think the government is after Suu. Centaurea's place on this is simply marked as "?".
Occidental Otaku: A lot of her assumptions on how things work are based on anime, manga, and video games.
Only Sane Woman: In Chapter 12, she more or less spends the entirety of Meer's jealous rampage pointing out just how crazy she's acting. In general, she's the reasonable girl of the lot, who doesn't try to push Kurusu around as much as the others.
Phenotype Stereotype: Blonde-haired, blue-eyed girl? Check. Foreigner? Check (she's most likely from Europe given her knightly background).
Broken Masquerade: Prior to her appearance slimes were still considered fictional creatures and, thanks to Ms. Smith not wanting to bother, are still thought of that way outside of the people she interacts with.
The other girls didn't even know humanoid slimes actually existed, which made them fictional to both worlds.
Dropping The Bombshell: At the end of of Chapter 13 she reveals that she can speak in more than just mimicked phrases, as well as her feelings.
Suu: "Well, it was Suu's fault that you caught a cold... I should apologize as well. But Suu doesn't mind! Because she loves her Master!"
The Empath: In Chapter 13, the answer to whether or not she could read thoughts from chapter 8 is answered. She's apparently able to figure out the basic emotions of people when she puts her antenna to their forehead.
As she's made entirely of some liquid-like substance, she becomes "diluted" when submerged in a bathtub-sized body of water, and takes time to reform and drag herself out of it. If she falls into a huge enough body of water (e.g. a river) or gets caught in a heavy storm, however, the dilution effect would be serious enough to kill her.
On the opposite side of the coin, dehydrating her shrinks her and makes her lose her humanoid form and revert to a compact blob, but doing so is akin to starving her. Most of the hijinks revolving around her involve her attacking anyone with even a trace of moisture on them.
Morphic Resonance: Regardless of whether she's in blob, child, or adult form, or mimicking another person, she always has her antenna.
Obfuscating Stupidity: While no one is sure how long she's been able to, she accidentally reveals that she can speak in more than just mimicked phrases. As soon as she's called out on it, she goes back to mimicking.
She's also the one to put the kibosh on the Director's plans to sell Papi's egg (and more than that, her dignity) by reading his mind and broadcasting his true intentions for all to hear.
Telepathy: In addition to knowing the emotions of people she's touching, she can see their memories as well.
Voice Changeling: She can mimic a person's voice precisely depending on the persona she takes on.
Your Size May Vary: Her raincoat's length seems to adjust along with her size when compared to her boots. While in her more childlike form, it looks like a Badass Longcoat. While in her adult form it's barely any larger than a shirt, despite the boots still only going up about halfway to the knees.
A mermaid and the fourth girl to officially move in with Kimihito (Ms. Smith has, unsurprisingly, considered Suu to not be her problem). Wheelchair-bound for obvious reasons, she first meets Kimihito when she loses control of it and he saves her. After she helps him find the other girls, it's revealed the waterproof room being built in Kimihito's house wasn't for Suu at all. Instead it was so Ms. Smith could dump her off on him.
Modest Royalty: In the "dresses like a commoner" sense, not in the "too modest to spend an entire chapter either in a bikini or out of it.
Marshmallow Hell: It's what Kimihito gets after saving her from her runaway wheelchair in their first meeting.
Nightmare Fetishist: Wants to experience a "tragic love" like in the original Little Mermaid story, including turning into sea foam!
Our Mermaids Are Different: Apparently they have webbed hands, fin-like ears, gills along their rib cages, and a pronounced set of pelvic fins. Also they can survive on land so long as there is a decent amount of humidity, and give off a mucus-like secretion to retain moisture.
Perky Goth: Dresses in the Gothic Lolita style, but has a very warm personality.
Shipper on Deck: She wants anyone but herself to be with Kimihito, primarily Meer as she was the only one to openly acknowledge being interested in him.
Too Kinky to Torture: After eating some of Meer's cooking, it brings to mind having her fins painfully split apart into legs, described as torture that could only be found in hell. Afterwards, she is seen collapsed on the floor smiling about it, despite foaming at the mouth.