As a doctor and a scientist, Shinra is interested in what he considers interesting phenomena, such as Shizuo's strength and Celty's body. It is later revealed that he performed plastic surgery on the body of Mika Harima to make her head look like the head of Celty. His reason was to keep Celty from finding the head so she could stay with him. Shinra seems to have the capacity to tell what Celty is feeling, much to her surprise, since she does not have a face to display her emotions. It has also been noted that he intends to marry Celty.
He is responsible for introducing Celty, Shizuo, and Izaya to each other.
Shinra has brown hair and eyes. He is always seen wearing a lab coat and glasses.
Shinra is considered odd and eccentric by many other characters, including his father and close friends. Because of this, his only friends in high school were Izaya Orihara and Shizuo Heiwajima, who were also considered weird and avoided by most of their classmates. Unlike Izaya, however, Shinra claims to have no love for humanity. He shows an obsession with the supernatural, particularly Celty's body and Shizuo's strength, and he loves to attempt to understand and explain them. He is shown to be a determined person, whether in winning over Celty or dissecting Shizuo, and he frequently switches among the Japanese first-person pronouns, believing that the pronouns a person uses for himself should change depending on with whom he is talking.
Shinra is the son of Shingen, a doctor, who since Shinra's childhood would have him participate in surgeries, the most notable being a vivisection on Celty after he discovered her on a ship when he was four years old. In exchange for permitting Shingen and Shinra to vivisect her, Celty was provided a place to live and remained Shinra's roommate for twenty years.
Shinra attended the same primary school as Shizuo, where he developed his fascination with the latter's unlimited strength and developed a theory about Shizuo's bones breaking under stress and healing quickly to become even stronger. He visited Shizuo in the hospital and asked to dissect him. Shizuo broke his arm is response. Shinra is one of the few who enjoys seeing Shizuo use his full strength.
Shinra attended the same middle school as Izaya and has been friends with him since. The two of them formed a biology club together but the members rarely ever did anything. When a club expo was scheduled, Shinra left their presentation entirely in Izaya's hands and, much to Shinra's surprise, Izaya turned the whole club into a gambling ring with one of the other members, Nakura, serving as Izaya's business partner. Shinra told Izaya to stop but got brushed off each time. One day, after making a bad bet, Nakura comes in brandishing a knife and threatening Izaya to give back all the money he lost. When Izaya refused, Shinra jumped in the way of the knife at the last minute and fell to the ground. Izaya called an ambulance as Nakura flees but asked Shinra to tell everyone that Izaya stabbed him. Shinra was confused but agreed, and in return Izaya promised to make Nakura pay for as long as possible for what he did.
In high school, Shinra introduced Izaya to Shizuo, beginning their murderous relationship. To some point, Shinra did enjoy the constant fighting between his two friends, but at the same time he blames them for ruining his high school days, saying that because of them he got much better at dealing with broken bones and stitching wounds.
He describes Shizuo as violent and Izaya as "shady as hell," so no girl was willing to approach them. In his opinion, Shizuo is true to his emotions in the same way Izaya is true to his own desires, though he would have preferred the latter to have desired money or women instead.
Dollars/Mika Harima Arc
Shinra is first seen carrying a video camera and filming people around Ikebukuro, asking them if they know anything about the Black Rider. He turns the camera on himself and begins telling Celty's story. When Celty asks what he is doing, he responds, "filming the story of them for generations to come."
Shinra met a painter in a city park drawing an Irish dullahan carrying her head, frustrated because he could not get her face right. Shinra complements him on the drawing, stating that she is perfect the way she is.
The next morning, Celty asks Shinra what dreams are. Being their day off, Shinra turns off the WiFi connection and shuts off his phone. Shinra's explanation is that even scientists do not know for sure. On a whim, Celty offers to cook for him. Shinra begins crying over the food she makes him because it tastes so good, but Celty misinterpreted his response, believing he hated the food and did not want to eat it, so she traps the food in a sphere of her shadows and leaves the apartment. A short while later, a man enters their apartment and tells Shinra that he has a job and should not turn his phone off, even on his days off. Shinra goes with the man to Yagiri Pharmaceuticals and he is told to erase the memory of a man who had stormed the lab with fireworks. Shinra told them memories are hard to replace and threatens the lab workers to release the man after the operation. When he leaves, he meets up with Celty and the two go to Russia Sushi for dinner.
As the restaurant is out of fish, Simon gives Shinra strange sushi. He gives Celty one of his fortune cookies. His own fortune reads "unrequited love." When Celty asks him to read it aloud, he quickly eats his fortune and claims his cookie did not have one.
The next night, Celty comes home upset, telling him that she found her head on a other human's neck. Shinra tries to convince Celty that she might be unable to retrieve her head, upsetting her. The next night, when Celty learns that the resemblance between Mika Harima's face and her own is the result of surgery by an underground doctor, Celty storms home and yanks Shinra up by his collar. He openly confesses to performing the surgery and states that he knew Celty's head was at Yagiri Pharmaceuticals all along. He hid the truth from her because he knew that finding her head was her one reason for staying in Japan, and he is afraid that when she finds her head, she will return to Ireland. He loves her and believes she is perfect as she is, without her head. He tells Celty to punch him, and she does. Shinra then asks if he can punch her back, and returns the favor by hitting Celty's helmet off. He says that she looks good in her natural state, and Celty hugs him, forgiving him.
Celty comes home and tells Shinra that she was attacked by the slasher. She believes the slasher is inhuman because of a feeling she gets around fairies and other supernatural creatures. Shinra tells her about the legend of a demon blade called Saika that seeks to spread its love of humanity by cutting people and controlling their actions. His father, Shingen, used to own the blade, but it disappeared ten years prior when he sold it to an antiques collector.
Shingen visits and stays with Shinra and Celty. Shinra is delighted when she confirms to Shingen her love for Shinra. Shingen states that Shinra was a strange child and is unsure where Shinra got his weird interests. While talking with the couple, Shingen accidentally admits to using Saika twenty years prior to separate Celty's head from her body and bring it to Japan.
One night, Celty brings home the demon blade called Saika. The blade is wrapped in her shadows, and she warns him not to touch it. However, Shinra fearlessly picks it up and notes the "Made in Japan, 2009" engraved into the blade near the handle.
Yellow Scarves Arc
Shinra comforts Celty after she is chased and intimidated by Kinnosuke Kuzuhara. Later, Anri stays at their apartment to avoid being hunted down by the Yellow Scarves. The next night, Shizuo walks in injured. Shinra asks him how he can walk after being shot, but Shizuo just tells him to heal him already so that he can go out and kill Masaomi Kida, the person he was told who ordered the shooting. Listening from another room, Anri runs out of the apartment with Shinra chasing after her. Shinra calls Celty to tell her that he is unable to keep up with Anri, and he falls over.
Shinra is contacted by Kasuka Heiwajima to treat an injured Ruri Hijiribe. Shinra rushes over to Kasuka's apartment and does his best to treat Ruri's injuries. He is amazed by her exemplary healing abilities and the fact that her skin is a lot harder than it looks. He gushes over Ruri for a short while, and after asking for Ruri's autograph, he is disappointed to be called away to Russia Sushi by Simon and Denis to treat a heavily wounded Egor. Egor mistakes Shinra for Shingen, peaking Shinra's interest. For taking him away from Ruri, Shinra charges them 200,000 yen, which is paid for by Mairu and Kururi, who have joined them in the back of the shop. He steps outside to make a call to his father, asking him what he knows about his Russian client. Shingen explains that Nebula sent Egor after Ruri to bring her in for experimentation, as she is another mythical creature like Celty.
As he is walking home from Russia Sushi, he is swarmed by the paparazzi, who had earlier seen him leaving Kasuka's apartment building. Shinra threatens them with violating his likeness rights and pushes his way through the crowd of reporters, running all the way home.
When he arrives at home, Celty is in a cocoon of shadow in the living room. Shinra falls inside the cocoon with her, where she simply wants to be consoled for getting into trouble with the police again and losing the one million yen she had wanted to spend on Shinra and herself. Shinra hesitantly offers Celty another job request and she accepts, since she needs something to take her mind off of losing so much money. When she leaves, Celty forgets to undo the cocoon and Shinra is left in there for several hours, wondering if he is being subjected to abandonment foreplay. After several hours, Shiki and several of his subordinates in the Awakusu-Kai enter his apartment asking about Ruri and break him out of the cocoon so he can rush to the bathroom.
Several days later, Shinra, Celty, and Emilia host a hotpot party at their apartment, and they invite most of the main cast except Izaya to join them.
Shizuo takes the scared Akane over to Shinra's apartment after she tried to tazer him. While he questions Shizuo, Shinra notices Akane has a fever and puts her to bed. Shinra examines the tazer gun Akane had and finds that it is much stronger than normal and that it could kill if used correctly. When Akane wakes up, Shinra does his best to ask Akane what she was thinking when she attacked Shizuo but when she mentions Izaya, Shinra immediately puts it all together. Shinra expects Shizuo to fly into a rage and turns around to find that Shizuo was actually smiling, lightheartedly and trying to comfort Akane. When Shizuo leaves, Shinra begins to wonder if Izaya has grown tired of living.
Dollars and Blue Squares Arc
Celty soon arrives to drop off Anri and Shinra lets her stay for the night. The next day, when Anri is about to leave to meet Mikado and Aoba, Shinra suggests that she take Akane with her, which she does. Soon after, Shiki comes into Shinra's apartment and informs him that Shizuo is suspected of murdering several members of the Awakusu. Shinra examines the photos of the corpses but remarks that it was too clean to have been done by Shizuo (If Shizuo really meant to kill them, then there wouldn't even be any bodies left to identify). Celty then arrives with Akane and the two of them hand her over to Shiki who hands her over to her father. Shinra and Celty then hear an explosion outside and Celty tells Shinra to take cover while she investigates. Shinra isn't seen again until the end of the novel where his and Celty's lives are slowly returning to normal.
Throughout the novel, the chapters are separated by "the lovey-dovey prattles of an underground doctor" which are basically just Shinra's commentary on the events that transpire though out the books but he always steers it to a conversation about Celty.
Daily Life Arc
Shinra and Celty are on a date but are repeatedly interrupted by various callers. The last one being Izaya, who calls them from the hospital due to boredom. Shinra gets progressively more irritable with each call.
Mikado and Aoba deliver a warning to Shinra and Celty about a man named Kisuke Adabashi. They say that Adabashi is a stalker of Ruri Hijiribe who is hunting down anyone close to her and, since Shinra was spotted leaving Kasuka's apartment shortly before Ruri and Kasuka were revealed to be a couple, Shinra could be in danger. Aoba returns the next day wanting to extend a hand of friendship towards the two of them but Shinra and Celty are suspicious since Aoba gave off the same vibe that Izaya does. When Celty leaves, Shinra threatens Aoba with a scalpel saying that if Aoba ever tried anything that put Celty in danger then it wouldn't end well for him.
Shortly after Aoba leaves, the apartment is attacked by Adabashi and his men who brutally torture Shinra for information on Celty. Shinra refuses to talk through all of the pain and Adabashi leaves him bleeding on the floor. Celty rushes home and finds Shinra bleeding profusely. She holds Shinra in her arms as he passes out.
Dragon Zombie Arc
Shinra manages to survive although he has to remain in a full body cast. Celty and Emilia do their best to take care of him but his naturally energetic personality keeps reopening his wounds. Shinra senses Celty's desire to find the one who did this to him and tries to console her. He tells Celty that if she finds Adabashi, to tell Shinra before she does anything so that they can deal with him together. Celty asks what Shinra will do to enforce this but Shinra replies that all he can do is cry and scream if Celty disobeys him. Celty agrees, sensing that Shinra really wouldn't hesitate to cry despite being over 23.
While cleaning his bandages, Celty notices another, older looking scar on Shinra's side and asks him about it. Shinra tells her of when he met Izaya and the events leading up to his stabbing back in middle school.
Kadota's Coma Arc
Shinra formed a small group to share useful information. Celty is the leader. The members are Walker, Shingen, Emilia, Namie and Mika. Later on it becomes a big influence on color gangs in Ikebukuro but nobody knows at this point.
Final Curtain Arc
Shinra is kidnapped by Kasane Kujiragi and is made into one of her Saika children. Kasane then forces Shinra to proclaim his love for her, which causes Celty to go insane. He is then taken by Kasane and later Vorona.
Shinra awakes in one of Kujiragi's apartments. He has overcame Saika's control relatively quickly. He is bloody, red-eyed, and in his pajamas. He then meets Manami, when he leaves the room, and she helps him make his way to find Celty, as he shares to her about Izaya.
In an alley, Shinra meets Kujiragi, who confesses to loving him, but he rejects her very gently. He likes her, but everything he is, is built on Celty, and so Celty is the natural choice. Later, Shinra meets Shizuo, then he goes up to the roof where Mikado, Masaomi, Anri, Saki, Seiji, Mika, and Celty are at.
Shinra sees through Celty's lies of amnesia. What she really wants is to leave Ikebukuro because she is now fully aware of how far from human she truly is and her true duty as a dullahan; and so she lies to everyone to minimize the hurt. In truth, she may have all of her memories back, together. She denies Shinra of his accusations and rides away into the sky to never come back, her thinking to have resolved all the trouble she has caused in Ikebukuro. Once she was in the air, Shizuo came and Shinra has him fling him into the sky after her, not just as punishment for what he has done but as well as his means to do what it takes for his love to come back to him and to show there is another way. He then cuts the link between Celty's head and her body (as she gets her memories back before anything else) when she catches him-with Kujiragi's Saika, which he rented from her. Celty saves Shinra and herself with her shadows. In the end, Celty stays with the love of her life, Shinra.
At the end of the arc, he and Celty are chased by Kinnosuke.
A year after the end of the previous series, Shinra spends half a year touring Japan with Celty. During the couple's stay in Akita, Shinra spots Yahiro fighting a group of delinquents. Shinra praises the boy for being energetic and tells him about Ikebukuro, which prompts Yahiro to move there. Shinra comes to greatly regret this later on when inaccurate rumors about Yahiro's alias, Snake Hands, having a romantic involvement with Celty start to spread.
It is shown that Shinra is still in the possession of the Saika blade that he received from Kujiragi, which he keeps in the form of a scalpel. He decides to slash some people in order to find the Slugger but Celty talks him down before he can do anything.
- Main article: Shinra and Celty
- Main article: Izaya and Shinra
- Main article: Shizuo Heiwajima
They were classmates in elementary school, where Shizuo's abnormal strength earned Shinra's attention, and he constantly asks Shizuo to let him cut him open. They end up attending separate middle schools, but meet once again in Raijin High School, still pestering him about at least getting a blood sample. Though there are many times when Shinra is nearly damaged by Shizuo, it doesn't seem to deter the other from continuing to annoy him. Even after high school, Shizuo repeatedly barges into Shinra's apartment to make uses of his "doctor" services, either to patch himself up or someone else. Shinra will not refuse a request from Shizuo's brother Kasuka, out of fear Shizuo will beat him up.
- Main article: Shingen Kishitani
Shinra and his father Shingen have a fairly stable relationship. When he was a child his father would let Shinra join him in performing surgeries, including the one where he dissected Celty. Shingen believed that Shinra has always been a "sicko" since besides his love for Celty, he believes Shinra enjoyed the past dissections "too much". Beside that he genuinely loves Shinra. Shingen cut Celty's head off and sold Saika's sword off to Anri's parents in order to protect Shinra from Namie's grandfather who threatened to kill Shinra if he didn't. When he discovers that Shinra was beaten up by Ruri's stalker, and Seitarou could have prevented it, Shingen doesn't hesitate to call Seitarou and warn him that he'll "smash his face" for what he did. He even goes to the dojo and asks Eijirou to teach him the deadly punch he knows so he can go get back at Seitarou.
- He sang DIAMONDS in the rapping CD.
- According to his profile card in the official DVD 6:
- He likes everything about Celty, proverbs/idioms
- He dislikes abstinence
- His hobbies are dissecting, games, and Celty.
- His favorite foods are three-five-eight marinaded sandfish and Celty's cooking.
- His least favorite food is the fat in meat.
- His favorite saying is "Neither doctors nor the Kusatsu Hot Springs can cure the illness called love" as well as every positive proverb about love.
- There was a rumor in his school that a girl with unusual tastes had confessed to him before, only to be rejected with the strange words, "But you have a head."
- Like most characters, he is a fan of Ruri Hijiribe.