Kimihito has a number of relationships with monster girls/subspecies either living with him or those he had been acquainted with outside his home.
House Guests
These girls are members of his household as he has been asked to be their host. Each of them have a special affection for Kimihito as they have either fallen for him or been attracted towards him due to his kind heart and acceptance for who they are as girls and doesn't mind what they are.
Miia
Kimihito and Miia
The first monster girl to move into his house. Miia is deeply in love with Kimihito after witnessing his kind heart and deep concern for her despite being a Lamia. Since then, Miia has always referred to him as her "Darling." She always tries to seduce him through flirting and shamelessly trying to make love to him, the end result, however, leaves Kimihito in pain. She is very possessive of him; becoming very irritated whenever another girl makes a move on him, causing Miia to become very clingy and jealous after more monster girls begin to move in.
Miia often fantasizes about Kimihito while she is in the middle of an activity or after a moving event. However, she often becomes shy and embarrassed whenever Kimihito does something perverted (albeit accidental) towards her and responds by calling him an idiot or a pervert. Her fervent desire is to become his one and only beloved and ultimately have a family with him.
Due to the Extraspecies Cultural Exchange law's prohibitions, Kimihito is initially reluctant to view Miia and the other girls in his household as anything more than close friends. However, after Ms. Smith informs him about "changes" within the Extraspecies Act that would allow him to marry one of the girls, he begins to genuinely consider the possibility of pursuing a good relationship with her. However, the extent of his attraction towards Miia in comparison to the other girls (except for Papi and Suu whom he views primarily as children) has yet to be made clear.
Papi
Kimihito and Papi
The second monster girl to move into his house. Papi first kidnaps Kimihito for no apparent reason, but it was revealed that she was running away from her previous host, which was Sumisu. Even though they were strangers at first, Kimihito risked his well-being to help Papi when she was in a dangerous situation, though he assumed her to be a child at the time. After witnessing his kindness and willingness to protect her, Papi decided to live with her new "Boss", causing her to fall in love with him.
Papi often plays around with Kimihito, initially viewing him as a "big brother" as well as her lover. She is a bit clingy and possessive of him, only due to her desire to play with others, until Suu appeared, Papi became less clingy towards Kimihito, but still desires to marry him one day. When Papi was about to lay an egg, she requested that only Kimihito was to help her.
Due to being a Harpy, she is very dim-witted and childish. This makes Kimihito view her more as a "younger sister," as opposed to a potential marriage candidate.
Centorea Shianus
Kimihito and Centorea
The third monster girl to move into his house. Cerea crashes into Kimihito when he was grocery shopping, causing her to believe their meeting to be fate as she may have found her master. He, however, explains that it wasn't exactly fate, but an accident. The two chase after a purse snatcher and Kimihito protected her from the criminal who was using her sword. After his act of heroism, Cerea tells him to refer to her by her nickname and she developed a strong sense of loyalty to him, referring to him as her one and only "Master."
Since then, Cerea became more shy and flustered due to her love for Kimihito, but tries to be more level-headed and calm about her feelings. Even so, she wishes to further her relationship with him as she tries to be intimate and a bit possessive, however she feels more obligated to be his faithful "knight" as she tries to follow her race's customs and would feel ashamed of engaging in something that may embarrass her. She even fantasized a few times about being married to Kimihito and bearing his child to start a family.
Kimihito is aware of Cerea's foreign nature and, as such, her inability to fully grasp the concept of Japanese culture. While slightly intimidated by her strength and combat prowess, he nonetheless looks upon her as a close friend and (following the amendment to the Extraspecies Act) begins considering her as a potential marriage candidate. After being appointed by Cerea as her master, Kimihito is often seen riding on her back.
Suu
Kimihito and Suu
The fourth monster girl to move into his house, albeit unofficially. Suu snuck into Kimihito's house looking for water sources and resulted in getting the guests wet. She makes her appearance in front of Kimihito while he was bathing with Cerea(after the centaur fell unconscious). She proceeded in "communicating" with him by mimicking Cerea's previous actions, such as scrubbing and embracing him. Suu developed a liking towards him, but remains childish and quiet. When she was about to fall into a river, which would have killed her, Kimihito saved her and welcomed her as a member of his house, though he had to make sure that she wouldn't wet anything else.
Suu fell in love with Kimihito after he showed kindness to her by giving her his umbrella when she was outside during a rainy day. This resulted in him catching a heavy fever and being bedridden. Suu knew that she can cure his ailment by feeding him purified water from her body. After he was healed, she finally spoke in her own words and voice by announcing her being the one to blame for his illness, but does not mind apologizing because she loves her "Master."
Like Papi, Kimihito tends to view Suu as a child or "little sister" as opposed to a potential marriage candidate. He sometimes gets a bit irritated when Suu unintenionally suffocates/drowns him through her embrace.
Meroune Lorelei
Kimihito and Meroune
The fifth monster girl to move into his house. Mero first meets Kimihito when she was testing her wheelchair as a means of mobility on land which causes her to roll down a steep hill and crash into him. She was very grateful for his help and kindness, including in saving her from a wild Suu. Sumisu revealed that Mero is the next one to move in, but the others weren't very happy. Mero developed an admiration and a desire of tragic love for Kimihito, leading her to refer to him as her "Beloved."
Because of her desire for "tragic love" from Kimihito, Mero would make several attempts to make herself the victim of said love, even when he happens to have an intimate moment with another girl, when he or herself would be on the verge of dying or dramatically leaving him behind. She soon realizes that her obsession is not as fulfilling, but still acts friendly and warm towards Kimihito as she is truly in love with him, just in her own "weird" way.
Their relationship was slightly strained when she tried to make love to him, thinking he was going to die anyway. He then referred to her as a "crazy tragedy freak" (though this was likely more out of anger and frustration then out of spite and hatred.) after that, Mero believed that Kimihito did not love or even like her, though Kimihito has denied this. He truly cares for Mero. In chapter 37, Mero tried to save Kurusu from dying in the water and gave CPR to him.
Kimihito takes care of her knowing that she is practically immobile on land and would require assistance. When not in her wheelchair, he often carries Mero bridal style and always tries to put her well-being and happiness first.
Rachnera Arachnera
Kimihito and Rachnera
The sixth monster girl to move into his house. Rachnera kidnaps Kimihito when she lured him into an abandoned warehouse and began to torture/play with him to break his "tough guy" act. In the midst of this, she became slightly perverted around him and changed her initial outlook on Humans when she discovered that Kimihito's kindness is genuine. She accused him of being attracted to her upper-Human half and being disgusted with her lower-Spider half, but he states that her legs are charming causing her to call him a pervert. She soon developed a strong liking to Kimihito and he agrees to become her homestay.
After moving in, Rachnera began referring to him as "Honey" and openly flirts with and makes sexual advances towards him. It is unknown whether she does this because she loves him or to just simply upset the other homestays. She once stated that she sees Kimihito as her "toy" and takes great sexual pleasure in making him her "hostage".
Kimihito initially viewed Rachnera somewhat as the troublemaker in the family due to her constantly making the others angry through her cynical and playful persona. When they first met, he always tries to compliment her features, knowing how self conscious she is about her appearance and even risked himself to help her escape. When Rachnera's former host arrives to take her back and claims to be ready for anything, Kimihito refuses as he states that she is a person, not a challenge, causing Rachnera be moved by his kindness which lead her to get drunk and admitting her love for him.
Lala
Kimihito and Lala
The seventh monster girl to move into his house. Lala first appeared as a Grim Reaper threatening Kimihito's possible death if he were to marry one of his homestays. It was believed that she is a stalker who was sending death threats demanding him to not marry. She was prepared to execute him, but had dropped her head somewhere and became distressed causing Kimihito to help her find it. While her body was being sexually toyed with by Rachnera, the others retrieve her head and return it to her body. She constantly tried convincing Kimihito and his homestays that she is the grim reaper and warning them that he is on the brink of death, recalling all the pain and suffering he went through with them.
After the sequence of the girls trying to help him escape death, Kimihito finally had enough of their gullible behavior and announced that he is not afraid and that there is no such thing as fate causing Lala to become nervous. Sumisu reveals that she was simply spouting difficult sayings and her reason for appearing was due to her concern for his well-being (wondering why he does not die whenever he is close towards death). She decided to stay and observe him in the meantime, but also to get away from Sumisu.
After a series of near-death experiences due to the girls' clumsy attempts to get closer to Kimihito, Lala encounters him a few times and states that he is constantly fighting death due to what he does for others out of the kindness of his heart, finding him as well as his strength and fortitude rather interesting. She, however, is not exactly interested in marrying Kimihito, but claims that his soul will belong to her when he dies.
Kimihito initially viewed Lala as hopeless and delusional due to her accidentally dropping her head and her constantly trying to convince him, others and possibly herself that she is a manifestation of death. He was not afraid of her and decided to let her stay. Over time the two have grown close and share a special relationship. Whenever Lala is distressed or worried he happily gives her advice and comforts her.
Monster Ops: Neutralization/M.O.N.
These are Kimihito's bodyguards and coordinators for the Cultural Exchange Program who are often called in to assist and/or protect him.
Kuroko Smith/Sumisu
Kimihito and Kuroko
As Kimihito's "Cultural Exchange Coordinator", Sumisu often drops in his household to check up on him and his homestays, constantly reminding him of the prohibitions and its consquences as she was the one who often made him the host of a number of monster girls. Due to her being quite irresponsible, Sumisu only shows up when the situation is inconvient for him; often providing information when its too late and has a tendency to mooch off of Kimihito for free homecooked meals. She tends to manipulate Kimihito through threats based on the Cultural Exchange and its prohibitions, warning him not to hurt or have sexual relations with a monster girl, otherwise the girl will be deported and he would end up in prison. Sumisu takes an amused liking towards Kimihito and refers to him as "Darling" after hearing Miia calling him that, albeit she finds the endearing term amusing.
Despite her irresponsible and somewhat lazy behavior, Kimihito is grateful for her assistance and protection. He does, however, become rather annoyed and frustrated with her constantly waiting until the last minute to inform him with needed or important information concerning his homestays, random/new subspecies he happens to encounter or his own house repairments, food supplies and finances/expenses. Sumisu appreciates Kimihito's willingness to care for the subspecies he was given and he appreciates her acting as a "guardian" to him whenever he is in trouble.
Tionisha
Kimihito and Tionisha
A member of M.O.N. and a somewhat indirect bodyguard of Kimihito. Tio seems to like him as she finds him cute and very sweet. During her date with him, Tio seems quite happy and cheery around Kimihito referring to him as "Snookums", however becomes visibly frustrated when he somewhat refuses to do what she asks, feeling that he can be a little more considerate and sensitive. When they were clothes shopping, Tio began weeping over how all the pretty clothing she wants never come in her size as they are too small, but quickly cheers up after Kimihito offers to adjust the size of her clothes in order for her fit into them causing the ogre girl to gleefully glomp him. She claims to greatly admire him for his good-hearted nature, but it is unknown if she is now attracted to him.
Kimihito finds it hard to keep up with Tio's level of energy and enthusiasm, but is aware of how innocent and sensitive she can be. Due to her bust size arguably being the biggest, he stares at her large breasts, but tries not to comment on her size knowing how self-conscious she is about her overwhelming measurements. Due to Tio wanting the pretty clothes she likes to fit her, Kimihito offers to adjust her clothes from now on.
Zombina
Kimihito and Zombina
A member of M.O.N. and a somewhat indirect bodyguard of Kimihito. Zombina seems to think of Kimihito as naive, but humorous. During her date with him, she makes the best of it by being a bit extreme and watch horror genre or Zombie themed films. She seems to take great pleasure in watching other people, mostly Kimihito whom she refers to as "Loverboy," lose their cool or become freaked out at the sight of scary things. When her hand fell off, Zombina takes him to a private place so he can sew it back on. She becomes both impressed with his skills and concerned with his rather calm demeanor, wondering why he isn't fazed by her. After he gives an honest and kind reply about her, Zombina becomes rather flustered by his kind words and decides to screw with his head by unstitching her breast and have him sew it back on, taking pleasure in watching him act nervous, until he accidentally pinched her nipple and tries to brush it off then laughing hysterically at the sight of Kimihito's nosebleed. She claims that he is a bit naive, but is grateful that he treated her as well as Tio and Manako as normal girls.
Kimihito often finds Zombina's behavior a bit extreme and slightly troublesome, but doesn't mind much because that is who she is. Despite her being a zombie and her claims, he is very concerned about her well-being and her feeling any form of pain should harm come to her. Even when she intentionally unstitched certain bodyparts for Kimihito to sew, he still offers to sew her body back together again if she asks. Due to how Zombina is seemingly used to others being freaked out or at least fazed by her, Kimihito always lets her know that she is a normal girl.
During their second date Kurusu tried to shield her from one of Shi Shi's attacks but failed. When she realized this she got angry but became embarrassed after he said she was still a girl. She later smiled after he tried to stitch her back together again, but soon became embarassed again when her breasts were exposed as he was about to put her back together. She soon thought to herself why she became embarassed, considering that he's seen her breasts before. It is implied that through these interactions, she is now attracted to him.
Manako
Kimihito and Manako
A member of M.O.N. and a somewhat indirect bodyguard of Kimihito. Manako seems to be slightly indifferent or a bit intimidated by Kimihito, acting somewhat nervous around him. During her date with him, she keeps her distance from him as she claims to not do well with crowds as well as having bad depth perception. She seems to wonder if Kimihito is genuinely a nice or kind person as others claim he is, recounting an experience in which Humans becoming visibly disturbed when speaking to her. She asks him, being professional and calling him by his real name "Kurusu", to look at her, believing that he too may be disturbed by her, but was surprised to see that he was looking at her as if she was normal causing her to become very flustered and embarrassed. She claims that her date was a bit embarrassing because he was the first person to treat her like a normal girl, but seems quite grateful and glad by his genuine kindness. It is unknown if she is now attracted to him.
Kimihito seems to think that Manako is somewhat hopeless due to being far away from him and crashing into objects during their date, but tries to put her comfort and needs first knowing how nervous she can be. He seems to understand how self-conscious she is about herself and as such tries to make her feel like a normal girl, not minding what she is.
During their second date he helped her overcome her fear of being in crowded public places by taking her to a festival while wearing a mask. Since she enjoyed it Manako asked him if they could do it again.
Doppel
Kimihito and Doppel (Kemomimi form)
A member of M.O.N. and a somewhat indirect bodyguard of Kimihito. Kimihito and Doppel haven't personally interacted with each other much. However, Doppel is aware of Kimihito's situation through Smith and her position in M.O.N., and like to meddle in his affairs. Eventually Doppel sent a death threat to Kimihito in hopes it would force him to stop being indecisive and choose a marriage partner, thus causing the "D" incident. When asked on her motivations for messing with Kimihito she simply said "Because it was fun."
When Kimihito apologizes to M.O.N. for the trouble he and Lala caused them, they decided to date him once again. Doppel decided to spend her date with Kimihito, whom she refers to as "Buddy", pranking a few people such as Lilith and Draco. While she puts on false acts and scenarios in order to trick Draco and lure Lilith into a trap seemingly enjoying the role of his girlfriend, Kimihito was able to help her capture a rogue Orc and as token of her appreciation said she is willing to do whatever he wants such as transforming into other monster girls for him to use and practice. Kimihito simply requested that she would wear clothing, something she usually refuses to do, but reluctantly puts on and wears the clothing he picked out for her.
Monster Community
Outside his home, Kimihito has had many encounters with the Monster Community, meeting and sometimes helping other Monster girls that come his way.
Polt
Kimihito sees Polt as a reasonable authority figure. The two seem to get along relatively well, as they teamed up to give commentary on Miia's and Mero's swimming race, and Polt gave him extra cat fish she had caught while doing community service with Draco, when his food budget was low.
Draco
As Draco loves Miia, she sees Kimihito as a rival and obstacle in her quest for Miia's heart, utterly clueless at the fact that Miia wants nothing to do with her and hates her. She supposedly hates him and attacks him on sight whenever she can, even if it brings her more righteous, well-deserved punishment. Karma always catches up with Draco in the end.
Kii
Kii's feeling towards Kimihito are mixed to say the least. The first time they met, Kii attacked him because of her distrust of humans, and the influence of chemicals she had absorbed. After Kimihito, Papi, and Suu helped her return to normal she warmed up towards him a little, as she allows him to take edible plants from her forest, but she can still act cold towards him if Papi and Suu are not with him. It's implied that she actually enjoyed Kimihito's action of sucking on her nipples.
Lilith
Lilith seems rather jealous of Kimihito as Rachnera favors him above others. She attempted to seduce him through her loli charms, assuming he was a lolicon, in order to blackmail him which would cause Rachnera to leave him, however he simply whacks her forehead and scolds her for the way she dresses. Shocked and confused, Lilith decided to use her succubus powers to hypnotize and allure him, only for Kimihito to repeat the same action and scold her. Frustrated, Lilith resorts to forcing herself onto him, only to be "caught" by Rachnera(disguised Doppel) and preformed a bondage on her as part of her prank.
Yukio
Luz Ninetei
Merino
Cathyl
Ton & Cott
Kinu & Liz
Potemkinme & Sabastian
Oct
Shiishii
Killa
Kino
Curie
Mil
Mili reveals her feelings to Kimihito.
A member and de facto leader of the Black Lily ranch. She meets Kimihito after he begins working on the ranch in order to make more money for himself and his guests, affectionately referring to him as "Mr. Newhire". Mil often acts as a kind guide for him at work and seems to see him as an incredibly reliable man.
While Mil initially treated Kimihito sweetly the same as the rest of the ranch dwellers, after he agreeing to perform the milking massage sessions on the minotaur girls to help them, she moved closer to him more, so much so that she came to admit that he united much more everyone on the ranch than herself. Later, after being amazed by the young man's efforts to help everyone at the ranch and because of the effects of her manual milking, Mil ended up becoming strongly attracted to Kimihito, showing off her softer side whenever she was with him. Indeed, of all the Minotaur girls who show interest in Kimihito, Mil was the most sincere about her feelings about him as well as the most vocal in her desire to make him live on the ranch, even trying up until to tenderly seduce him into the bath.
Monster Families
These are the relatives of Kimihito's house guests he had met when they either come to visit or were visited by Kimihito himself.
Miia's Mother
Papi's Mother
Centorea's Mother
Meroune's Mother
Humans
These are the humans who Kimihito have met and come into contact with.
The Racist Couple
He absolutely hates them for making the girls uncomfortable.
Neighborhood Kids
He cares about them but never really truly interacts with them.
Bicycle Police Officer
Kimihito had a few dealings with the cop.
First, Kimihito claimed to be Papi's host family and Smith arrived with the documents for the officer to confirm.
Second, after Kimihito was kidnapped by Rachnera, he unwittingly caused the cop to become aware of their presence inside an abandoned warehouse prompting the officer to find help.
Third, Kimihito was held at gunpoint by the cop for holding a girl's detachable head.
Purse Thief
Kimihito shared Centorea's dislike towards the Purse Thief who had been purse snatching in the area.
Kasegi
Kimihito initially was unhappy when Kasegi barged into his house without his permission doing some documentary. Suu blowing Kasegi's cover provoked Kimihito to attack the con man in order to protect the demi-human girls who were living in the Kurusu house.
Ren Kunanzuki
Ren Kunanzuki sought to take Rachnera back to live with her family and tried to get Kimihito to sign a contract. He refused to sign the contract saying Rachnera was a person not a challenge that the human girl would overcome and distrusted her by pointing out that Ren was too selfish in the extent that the Kunanzuki family would be unable to take good care of Rachnera like before.