Yoshikage Kira/Personality and Relationships

Personality
"I really want to reveal Yoshikage Kira's true nature to that girl on the right. I'd like to reveal my deep desires to her. I really want to touch her thin neck with my hands... and strangle her to death."

Kira is a serial killer, characterized as highly egocentric and psychopathic, with a few obsessive-compulsive tendencies. He is also a hand fetishist.

Kira longs for a peaceful life, safe from any worry, and does not wish for it to be interrupted. Whenever that peaceful life seems assured, Kira adopts a jolly and confident demeanor. Although he is highly intelligent and possesses many talents, this yearning shows in his dislike of coming in first, and he even made it a point to never rank better than 3rd in any competition so as not to stand out. Since his youth, Kira has been avoiding standing out, living a healthy life. He becomes bothered when someone disrupts his habits and goes to extreme lengths to get it back. As his father pointed out, this will to stay in the background was so bad that if bullied or denied his favorite toy, Kira would bite his nails until they bled, being the only way he's found to express his frustration.

However, beneath his façade of a simple, humble salaryman, Kira is very abnormal. The most abnormal characteristic of Kira are his frequent and periodic murderous impulses. Kira targets women, or, more specifically, women with beautiful hands. Kira possesses a hand fetish, which he discovered when he found himself aroused by the Mona Lisa's hands. However, his desire has never extended to the rest of the female person. This results in murdering random women, not caring in the least how they look like or behave, in order to acquire their (severed) hands as "girlfriends", acting as if the severed hands were actually sentient and conversing with them, even offering them various gifts. When one "girlfriend" begins to decay, he disposes of it and goes off in search of a replacement. Kira is an opportunistic killer, his modus operandi being spotting a potential victim, following her to her house, and murdering her when both are isolated. His Stand erasing any proof, these murders are actually reported as missing persons. Moreover, Kira has expressed various other similarly violent impulses such as the desire to choke his victims to death and has horribly scarred at least Reimi Sugimoto.

Apart from his murders, Kira is particularly violent when someone threatens his way of life or publicly humiliates him. Since Kira doesn't want to be noticed, he will try everything to solve his problems without facing anyone directly. However, if he doesn't have any other choice, he will instantly try to kill whoever discovers his true nature. Kira is quick to drop his polite demeanor, rudely insulting his foes or violently beating them before killing them. After Koichi's Echoes ACT 3 results in Kira making a fool of himself in public and attracting unwanted attention, Kira went on his way to torture and humiliate Koichi, putting his shoe into his mouth and slamming his face against the ground. Kira has a hard time controlling these impulses, as seen when Hayato Kawajiri threatened to blackmail him. Kira lost his calm attitude and murdered him despite knowing he couldn't afford such a mistake.

Kira is also afflicted with a number of other quirks. Apart from his wish for a monotonous and tranquil life, Kira's OCD also makes him very meticulous and thorough. Kira has sophisticated tastes, notably buying his lunch at the best store in town as well as wearing Valentino suits. He doesn't tolerate any imperfection, and is even willing to lose time fixing Koichi's socks, becoming agitated when he sees them being worn inside-out. Furthermore, during his time as Kosaku Kawajiri, Kira made sure to perfectly mimic his new identity in every way, notably Kosaku's hand-writing, which he trained himself to do conscientiously. Kira's solitary nature is partially stemmed from his disgust of people who don't behave as properly as he does.

Kira is also an egocentric and selfish man, akin to a spoiled child. He doesn't care that is crimes involve murder and make his victim's relatives suffer. He only seeks to satisfy his basic instincts. In addition, Kira is determined to preserve his lifestyle, and being set back only increases his determination. Kira is also quick to shift the blame to someone else for his troubles, notably the Joestar group, for ruining his life. Kira possesses a twisted pride in having managed to mix his tranquil lifestyle and his serial murders for so long, and categorically refused to flee the town and live in fear, preferring to maintain a shaky façade of normal life with the Kawajiri's.

In addition, while normally a very cautious meticulous man who ensures he leaves no evidence behind, there are a few occasions where he becomes overconfident and lets his guard down, and each time has led him to confrontation with the Joestar group or defeat at their hands. He once put his "girlfriend hand" in a sandwich bag and failed to notice Shigechi's prescence as he came to take the sandwich bag, thinking it was his. This would lead him to his first confrontation with the Joestar group. In addition, he left his jacket to a tailor at Centipede shoes and left his real name, forcing him to confront them. He was overconfident in his Sheer Heart Attack, believing it was invincible and leaving the scene but was forced to return to the scene of his crime when Koichi managed to subdue Sheer Heart Attack. In addition, he let his guard down near a wounded Jotaro, allowing Jotaro the opportunity to beat him. Finally, when he was overconfident he had beaten Hayato Kawajiri in his attempt to stop him, he blurted out his real name in front of Josuke by mistake which Hayato had planned.

Kira believes that he has luck and fate on his side, exposing a superstitious façade, claiming that whenever faced with an obstacle he will be able to make it through with a combination of hard work and opportunity. He measures and collects his own fingernail clippings, using them to predict his murdering luck off of their length.

When Kira was pierced with the Arrow, his demeanor became much more relaxed and prone to elation due to his new-found power, which guaranteed that anyone approaching Hayato would be killed. Ecstatic to possess a power which would dispose of anyone who investigated him, Kira allowed himself one loud boast, which caused his downfall as Josuke overheard him claiming to be "Yoshikage Kira".

During his confrontation with the Stand Stray Cat, Kira expressed a desire to protect his "wife"  Shinobu Kawajiri and even showed relief at her safety; A feeling that confused him, and Kira rationalized it as him merely not wanting to arouse suspicion. Whether these feelings were genuine or not is left unanswered.

As a ghost, Kira lost all memory of his previous life and has thus lost his temptation to kill. However, his desire for a peaceful existence and his latent brutality remained.

Family

 * Yoshihiro Kira: Yoshihiro is protective of his son, enough so that he was willing to support his son's murderous streak without a care as long as it made him happy. However, Yoshikage thinks little of his father, ignoring his advice of leaving Morioh and sparing no thought for him when he died. In the end, Yoshihiro died in the most ironic way possible, being blown up by his son's bomb after he was tricked by Josuke into doing so.
 * Mother: While little is known about their relationship and Kira's opinions of her, Araki points out that her overall appearance, as presented in their family portrait, suggests she may have been a bit overprotective of Kira to a point of abusive coddling.

Kosaku Family

 * Shinobu Kawajiri: While Kira impersonated Kosaku, his failed attempts at acting ordinary were mistaken by Shinobu for a change toward a bolder demeanour from her husband. Charmed, Shinobu became attracted to her husband, not knowing that it was Kira. Kira on the other hand first struggled not to act on his murderous impulses on Shinobu and tried his best not to attract attention, thus acting gently with her. As time passed, notably after protecting her from Stray Cat, Kira noted a burgeoning affection for her.
 * Hayato Kawajiri: Hayato and Kira lived in mutual suspicion, with Hayato noting everything his "father" did that was out of the ordinary, while Kira disliked the company of such a nosy child. When Hayato hears Kira plotting to kill him and then sees him use Killer Queen to kill a couple, their relationship turns antagonistic, culminating in Kira killing Hayato in a fit of rage. When Hayato becomes the catalyst for Kira gaining the sub-bomb Bites the Dust, Kira underestimates Hayato's resourcefulness, dismissing him as harmless at first, which Hayato exploits to lure Kira into the hands of his enemies. Hayato had come to know Kira well and proved an useful source of information during the climactic fight between Josuke and Kira.
 * Tama: Kira and the cat Tama were initially enemies due to Kira's interference in Stray Cat's revenge against Shinobu. Kira wanted to get rid of the conscious plant as it was likely to attract attention, but after distracting it, he decided to keep Stray Cat in the attic, planning to use it later. During his confrontation with Josuke, Kira made the most of Stray Cat's power by combining it with Killer Queen's detonation ability to produce air bombs.

Enemies

 * Josuke Higashikata: After Shigechi had been killed, Josuke developed a grudge against Kira and swore to avenge Shigechi. While Josuke loathed Kira, the latter didn't think much of Josuke and as an enemy, preferred to avoid any confrontation with him. However Kira noticed that Josuke's healing power and resourcefulness countered his Killer Queen's bomb power and was precautious against him during their fight.
 * Rohan Kishibe: Rohan was at first only curious about the local murderer, but after learning that he almost died by his hand and that Reimi protected him, his efforts for finding Kira became more personal. As an enemy, Kira preferred to avoid any confrontation with him. He was also aware of Rohan's status as a famous mangaka.
 * Koichi Hirose: Koichi, after learning of Kira's crimes, came to deeply loathe him to the point he would attack him on sight. Kira, on the other hand, came to somewhat praise Koichi's ability for being able to track him and then indirectly humiliate him in public, which he made sure to pay back with a beating. When Koichi humiliated Kira a second time, demonstrating how careless the serial-killer could be, Kira was enraged and came to detest Koichi, being happy at the prospect of Koichi dying.
 * Okuyasu Nijimura: Okuyasu, after learning that Kira killed Shigechi, developed a deep grudge against the murderer. As an enemy, Kira preferred to avoid any confrontation with him. Kira attempted to kill Okuyasu and turned him into a bomb. He was surprised when Okuyasu suddenly came back to life during his fight with Josuke.
 * Jotaro Kujo: The first time Jotaro would encounter Kira was near the Centipede shoe shop after Jotaro was heavily wounded by Sheer Heart Attack. Kira underestimated Jotaro due to the poor state he was in, only to get pummeled by Star Platinum for his trouble. Kira noted how dangerous Jotaro was and took care to avoid confronting him again. During the events of Bites the Dust, Kira mentions to Hayato that he would be very happy if Jotaro were to die in particular.

Victims

 * Reimi Sugimoto: Reimi was the first victim of Yoshikage Kira fifteen years prior to the start of Part 4 along with the rest of her family, including her pet dog Arnold. As a ghost, Reimi remained in Morioh, looking for someone to help her put a stop to Kira's murders in order to restore Morioh's peace and dignity. While Kira managed to remember her name when Shigekiyo mentioned her, he couldn't recognize her at first when they met fifteen years later, which Reimi theorizes as Kira not having the occasion to remember her since he didn't take her hand as a "girlfriend". After her archenemy was dragged away by the ghost hands of the alleys, Reimi was able to peacefully ascend to heaven.
 * Shigekiyo Yangu: When Shigechi unwittingly takes Kira's girlfriend, Kira saw Shigechi as a potential threat to his peaceful lifestyle. When both confront each other, Shigechi, shocked to learn that he is a serial killer and seriously injured when trying to fight Kira, tries to warn his friend Josuke in order to protect his family. On the other hand, Kira thought little of Shigechi and swiftly disposed of him, wanting to forget about his fight as soon as possible.
 * Aya Tsuji: The two had little interaction but Kira was aware of her occupation and abilities, which allowed him to escape the protagonists and change his identity. Before being killed by Kira, Aya describes him as truly terrifying and hated him for using her powers for evil.
 * Kosaku Kawajiri: The two had no onscreen interaction and Kira only accosted him because they were of similar height and build. He kidnapped Kosaku, dragged him to Salon Cinderella, killed him, and took his identity including his face, fingerprints, and hair. Kira however was annoyed by Kosaku's willingness to have a promotion, forcing Kira to stress himself by bootlicking Kosaku's superior while having to impersonate him in order to maintain his masquerade.