| Spoiler warning!|
This article may contain plot details about the game, anime and other media.
|Age|| 18 (physical age)|
Several centuries (chronological age)
|Physical and Vital Statistics|
|Height||180 cm (5'11")|
|Weight||64 kg (141 lb)|
|Occupation||3rd year High School Student|
|Relatives|| Kou (adoptive younger brother)|
Yuma (adoptive younger brother)
Azusa (adoptive younger brother)
|Game||Diabolik Lovers MORE,BLOOD|
|Manga||Diabolik Lovers MORE,BLOOD Anthology|
|Anime||Diabolik Lovers OVA|
|Japanese Voice||Takahiro Sakurai|
Ruki Mukami (無神 ルキ Mukami Ruki) is the oldest son of the Mukami household. He is known as the 'Brains' of the Mukami family.
Ruki is a handsome young man with short ruffled hair colored with black on top and white on the tips. He has blue-grey eyes and also three black piercings on his right ear. Ruki has two big scars on his back from when he was a child. He wears black web chokers on his neck. He is sometimes seen carrying a book.
He usually wears a grey jacket with a long sleeve black shirt underneath and wears it with black pants and a brown belt. He sometimes wears a long -sleeved maroon shirt with a black butterfly print on the bottom left side and wears it with black pants and a black belt. He wears the black web chokers with both outfits.
His school uniform consists of the black school jacket with a white dress shirt that is slightly unbuttoned revealing a long- sleeved maroon shirt underneath and a long black tie over it. He wears it with the black plaid uniform pants and brown shoes.
He always has an intimidating smirk on his face matched with a calm tone, but also has a sense of brutality can be felt in his spoken words. Without dirtying his own hands, he interacts with others as a cruel-hearted military do-S (extreme sadist). Ayato tends to mock him for his sometimes forced intellectual manners.
Ruki likes to view and treat the heroine like a livestock, not only because she is a human and he a sadistic vampire, but also because in his past he was treated that way by the stronger grown ups in the orphanage he lived in.
Before he was turned into a vampire, Ruki was a human born into a rich family. He was a spoiled little boy who was a member of the 'aristocracy' and found amusement in treating other people harshly and sadistic. However, as karma would have it, Ruki’s father, a kind and generous person, wasn’t good at managing his business/money and became bankrupt.
Ruki found out about his father's bankruptcy when he woke up to the servants ransacking the house for valuables. When he tried to stop them, they banded together to beat Ruki up for all the cruel things he did to them while telling him about the state of his family. To make matters worse, they told him that his mother ran off with her secret lover, leaving only a letter saying that she loves him. After the beating, Ruki went to the garden and found that his father had hung himself.
Ruki stayed behind in his family home for some time, hoping that his mother would come back (he even wondered to himself how his mother could say she loves him but leave him behind, which later affected seriously his trusting issues towards females and their capability of loving him) before he gave up and had to live on the streets, mocked by another aristocrat. He ended up in an orphanage where he was treated poorly by both the other kids and caretaker because he was a former aristocrat with a bad attitude.
The only kids who were decent to him were Azusa, Kou, and Yuma, and eventually the four of them devised a plan to escape their ‘hell.' Unfortunately, while the plan started off well, they were pursued and caught and most of them shot. Even though Ruki wasn't shot himself, as punishment for trying to run away, he was branded on his back like ‘livestock/cattle.’ As Ruki believed he was at the deepest pits of hopeless rage and despair at the world, Karlheinz appeared and offered the four children the chance to become vampires in order to take revenge on the world that, in his words, deprived them of everything if they agree to serve him.
Ruki, Yuma, Kou, and Azusa became vampires, and Karlheinz chose Ruki to be the ‘brains’ of the group, making sure that he was well-educated and capable of leading his ‘brothers.’ When he asked why Karlheinz chose to give him all this education when the others didn’t have that, Karlheinz told him that it was Ruki’s new role and that they’re all necessary for his plan. The plan details a human girl "Eve" with the heart of the demon lord’s daughter. "Eve’s" blood would choose an “Adam” who would be able to obtain the power to control the world, and their descendants would change the world. Ruki really felt indebted to Karlheinz, so he worked for him, doing what was needed to help him complete that plan.
However, later realizing an impure vampire (turned vampire) like him can never become the "Adam", made Ruki feel conflicted (in his route if he falls in love with the heroine). Because at one side he wishes to never betray his master/savior Karlheinz, and at the other side he doesn't want to give up the newly discovered bond and the so intoxicating blood. In DARK FATE, Ruki has the chance to become a human again because of the newly added skills of the blood of the heroine (Unlike Haunted Dark Bridal, the blood weakens and humanizes the vampires, negating the vampire virus as well as turning impure vampires back into humans those who weren't born as vampires.)
Ruki is the eldest son of the Mukami household. Granted by Karl, his job is to be the leader and look after his younger brothers: Kou, Yuma, and Azusa. Unlike the Sakamaki brothers, they have a closer relationship with one another and care for each other. His younger brothers respect him and follow his lead. Ruki's strategical thinking helps them to fight and cover each others backs even against stronger opponents. His mind helps him usually strategies and overcome the strength gap between them and pure born vampires, and even makes them survive and escape a direct attack from the First Bloods.
The Mukami love to have dinners together and they all praise Ruki's cooking. Ruki is talented in cooking especially in making soups. If the boys start arguing on the table, Ruki is the one to put them all in order, even though sometimes Yuma's free spirit makes the two males clash at least verbally. All of them respect deeply one another and help each other always. Even if not sharing blood ties, the Mukami have very strong family bonds with each other.
Ruki respects Karlheinz since he is the one who gave them a second chance at life, along with his brothers, thus saving him from the orphanage, or as he dubs it, "Hell". He feels indebted to Karlheinz, so he agrees to work with him for the "Adam and Eve" plan. Ruki has never fooled himself that Karlheinz does this out of "good heart" even though he respects him deeply and obeys him. He does want to know Karl's true intentions but would never question his decisions.
However, in Ruki's vampire ending in MORE,BLOOD, he doesn't mind betraying Karl in order to be with the heroine. He claims that he's the "snake who tempts Eve", but she agrees to be with him despite what he believes.
In DARK FATE, even though Ruki keeps being unfit to be an "Adam", Karlheinz's experiment takes the turn that makes it possible for Ruki to become a human again.
Ruki is very strict with Yui. Right off the bat, he forces her to sleep in his room so that he can monitor her at all times, thus giving her limited rights. He also forbids her to go to school since the Sakamaki brothers go there, but he eventually allows Yui to attend school normally. However, even at school, he still monitors her by making her attend his lessons, much to her embarrassment since he is a third-year student. When Yui gets attacked by Ayato at school, she tries to keep quiet about it, but Ruki sees right through her and ends up biting her in the stomach as punishment. At one point, Yui brings home a stray kitten, but Ruki kills it which upsets her and not being able to stand seeing Yui upset, he hugs her from behind to cheer her up.
One night, Ruki has a nightmare of his past and when Yui tries to comfort him, he loses control of himself and almost strangles her, but when he regains his senses, he kicks Yui out of his room to ensure her safety. When Ruki and his brothers finds out that Ayato has discovered their whereabouts, he locks Yui in the dungeon to protect her. After some time and with begging, he allows Yui to go out of the dungeon for a bit, but she's only allowed to be in his room. His time with Yui is short-lived when Ayato flies in out of nowhere and punches Ruki, knocking him out. Ayato grabs Yui and takes her out to the balcony, but Ruki manages to regain his consciousness, crawls to the balcony and he grabs Yui's hand, in an attempt to prevent her from being taken away. It is hinted that Ruki actually does care for Yui when he asks Ayato if he is taking her away because he loves her. Ayato laughs and says that Yui's blood is only delicious, then burns the Mukami mansion down, while taking Yui with him. Yui then resides in the Sakamaki house, only thinking about Ruki. After some time passes, Ruki appears before Yui in the garden and he tells her about his past in better detail than before, as well as the "Adam & Eve" plan. He then wishes her farewell since he has finally realised that he can't become "Adam" and she should choose one of the Sakamaki's instead because she's deserving to be "Eve". By then, Yui has realised that she has fallen in love with Ruki.
He is the main antagonist in Ayato's route and he appears more friendly, gentlemanly and caring towards Yui unlike his own route. When Yui passed out after Ayato forcibly sucked too much of her blood, he helped her to the infirmary causing Ayato to get irritated to find him with her. On one occasion, he tries to convince Yui to leave Ayato and to come with him instead, but she tells him she can't trust him, prompting Ruki to attack her and suck her blood by force. When Yui runs out of the Sakamaki mansion after being provoked by Ayato, Ruki meets her the in forest along with his brothers and they take her back to their mansion. After Yui finally realised her feelings for Ayato, she visits Ruki in his mansion to turn him down and he reveals to her that he was not being serious at all, it was only an act. However, in Ayato's Brute End, Ruki finds Yui wandering through the city streets upset about the fact that Ayato won't touch her or drink her blood. He approaches Yui and tells her that it seems as though she has become accustomed to having her blood sucked multiple times. He asks her if she would like him to replace Ayato though he considers it provoking to be a substitute. He sucks Yui's blood until Ayato discovers them (having had been told by Laito) and Ruki gets killed, followed by Yui.
Like all vampires, he has an inhuman strength as well as increased speed (less than a pureborn vampire), increased vision and hearing, and smell. Being a vampire, he also has fast healing though it is slower than a pure-bloods.
He appears to be capable of teleporting from nowhere in an instant.
He is very intelligent and is strategical in combat.
Impure vampires do not have the same amount of skills like pure ones, nor do they possess their own magic, however, Karlheinz borrows some for them, such as protective barrier and bat familiars.
However due to being former humans they are quite used to things like daylight and human food.
- He is right-handed.
- His foot size is 27.5 cm.
- The book he always reads is a memento from his father.
- His recent interest is making original dishes or recipes.
- He hates strong-flavoured food and drinks.
- He is skilled at cooking and even knows how to flambé.
- He knows how to ride a horse.
- He is fluent in Nordic and proficient in English.
- In his DARK FATE Brute End, Ruki and Yui have a son named Adam. Later, Adam appears to be a first blood and Shin Tsukinami's son.
- In episode 5 of the second season of the anime, he is shown to be reading Catcher in the Rye.
- He is rivals with Ayato and likes to taunt or provoke him when it comes to Yui.
|Sakamaki Brothers||Shu Sakamaki • Reiji Sakamaki • Laito Sakamaki • Kanato Sakamaki • Ayato Sakamaki • Subaru Sakamaki|
|Mukami Brothers||Ruki Mukami • Kou Mukami • Yuma Mukami • Azusa Mukami|
|Tsukinami Brothers||Carla Tsukinami • Shin Tsukinami|
|Others||Karlheinz • Beatrix • Cordelia • Christa • Richter • Seiji Komori|