Masaomi's usual attire consists of a white hoodie, black jeans, a pocket chain, a silver bracelet, a silver ring and black sneakers. Throughout the anime, he is often seen wearing the Raira uniform jacket over his hoodie with brown sneakers, though the novels note that like most students, he does not wear his school uniform.
During his time in the Yellow Scarves, he wore a black jacket with a white shirt along with his gang's titular accessory. He has dyed light brown hair and multiple ear piercings.
Masaomi has a very friendly, enthusiastic, and outgoing personality, and is almost always seen fooling around, smiling, making bad jokes, teasing his friends, and hitting on girls. He is shown to care deeply for his friends, having to act as a sort of big brother for Mikado as he adjusts to life in the big city and going to great lengths to protect those who are close to him. When Mikado first sees Masaomi in Ikebukuro, after years of separation, Masaomi's bubbly personality and bad jokes are what convince him that the man greeting him is indeed Masaomi Kida. As the series progresses, it is revealed that Masaomi's enthusiastic, happy-go-lucky demeanor is actually a mask of his true, much less secure self. He appears to agonize over major choices much more than any other character in the series, although he falls short of being paralyzed by his fears, still being able to make important decisions when necessary. He also demonstrates a feeling of responsibility for those close to him, taking attacks on his friends very personally. Despite appearing carefree, his experience as leader of the Yellow Scarves makes him painfully aware of the realities of life, and his greatest fear appears to be allowing himself or his friends to "cross over to the dark side," preferring that they stay completely away from the color gangs even to the point of being ignorant of them. As the leader of the Yellow Scarves, Masaomi has also demonstrated a ruthless demeanor when confronting his followers. He shows no hesitation at all when physically or verbally berating other members who go against his orders. Even members who are older than Masaomi seem genuinely intimidated by him.
In terms of abilities, Masaomi is shown to be a proficient street fighter, being able to easily incapacitate several of Horada's henchmen before being overwhelmed by sheer numbers, though he is no match for the likes of Ran Izumii, as shown when he broke his hand just by punching him.
Five years before the start of the series, on New Year's Eve, Masaomi witnesses middle schoolers being picked on by a group of high schoolers. He sacrifices himself to save the middle schoolers and is saved by Shizuo Heiwajima. He then encounters Kazane Kinomiya, and she inadvertently helps name his future gang by noticing his dyed scarf and mentioning the Yellow Scarves Rebellion.
One of the boys, Koji Yatabe, thanks him; Yatabe would later become one of his most trustworthy allies within the Yellow Scarves. They witness the Headless Rider, and Masaomi decides he would show it to Mikado if he ever came to Ikebukuro.
Masaomi ended up founding and leading the Yellow Scarves in middle school after people began gathering around him due to his fighting prowess. Although he had not intended for the group's whimsical formation, he was still at its core and decided its name and color based on a Romance of the Three Kingdoms motif. As the Yellow Scarves grew, they became one of the notorious 'color gangs' in the city, occasionally fighting other groups. However, as the gang members became older, one of their rival gangs, the Blue Squares, began to get serious, stretching the boundaries of a typical gang of middle schoolers and becoming quite violent. The Yellow Scarves naively expected a fair battle, but the Blue Squares allegedly played dirty and only picked fights that they could win, devastating the Yellow Scarves.
It was during the gang war that Masaomi met Saki Mikajima, a girl who recommended him to an informant named Izaya Orihara to help him fight his war. Masaomi was put off by Izaya's personality and found it difficult to trust him, but Izaya's advice was sound, giving the Yellow Scarves intel on Blue Squares hangouts and teaching them how to fight. The success Izaya brought to the Yellow Scarves led Masaomi to unintentionally become dependent on him for help, and Izaya continued to provide information until the Blue Squares was cornered and about to be finished off.
Thanks to Izaya, Masaomi and Saki saw a lot of each other until they agreed that they were dating. Saki was kidnapped and tortured by Ran Izumii and the higher-ups within Blue Squares in an attempt to lure Masaomi out and end the Yellow Scarves. Masaomi sought Izaya for help, but Izaya would not answer his phone, and Masaomi was left helpless and unable to save her. Fortunately, Kyouhei Kadota and his gang within the Blue Squares, who were disgusted by the gang leader's lack of honor, betrayed the Blue Squares and saved Saki, though with two broken legs and no family, she lived in Raira General Hospital for more than a year.
Masaomi left the Yellow Scarves after the war and vowed never to go to "the dark side" again. According to Izaya, however, Saki became the embodiment of a dark past from which he could never escape.
Throughout these events, Masaomi stayed in contact with his childhood friend Mikado, who was a world apart from the color gang wars in the city. Through chats with Masaomi, Mikado Ryuugamine decided to come to Ikebukuro, lured in by the sense of excitement and fun that his friend described. Hearing about how bored he was with his small town life, Masaomi encouraged Mikado to join him in the city and enroll at Raira Academy.
Dollars/Mika Harima ArcEdit
Masaomi is introduced giving Mikado an official welcome to Ikebukuro. Despite their time apart, the two get reacquainted quickly as Masaomi shows him around. He introduces Mikado to a few of the more notable residents of the city, including Simon and the van gang, while also warning him about a few of the more dangerous individuals to avoid.
Later, he and Mikado come across Anri being bullied and, just as they try to form a plan to step in, Izaya interrupts them by pushing Mikado into the fray. After things settle down and Izaya chases the bullies off, he asks Masaomi to introduce him to his friends. Masaomi reveals that he went to Raira Academy because of Izaya. They are interrupted once again by the arrival of Shizuo Heiwajima, who attacks Izaya with a trash can, to Masaomi's excitement. Mikado takes Anri's hand and runs, leaving Masaomi behind.
The next day, Masaomi, Mikado, and Anri go to the park where he buys ice cream for the whole group. He and Mikado then listen to Anri while she talks about her missing friend, Mika Harima. That night, he gets called over by Mikado because Mikado bumped into a girl on the street, brought her home, and does not know what to do.
Masaomi goes over to see the girl and to get a proper explanation. Mikado explains that the girl was being chased by the Black Rider, but Masaomi is more than skeptical, remarking that others would not believe his story either. He drives this point home the next day as he blurts out everything Mikado had told him the night before, intentionally telling the ridiculous story to several classmates so they would not believe it.
Knowing that Mikado was interested in the rumors about the Dollars, Masaomi takes him to the roof to see if Ryo Takiguchi is a part of the gang. Ryo tells them the truth, and says he is in the Dollars, explaining his view of the group in the process. At the end of the school day, Masaomi ends up in a big fight at the student council meeting, so he cannot walk home with Anri and Mikado.
The next day he tells Mikado about the Dollars meeting that happened the night before and that according to the stories, the Headless Rider really has no head. At lunch, Masaomi hits on Anri, causing Mikado to punch him in the face.
Masaomi sees Anri being harassed by her teacher, Takashi Nasujima. Masaomi steps in, pretending to joke about telling the teachers about Nasujima's actions. Nasujima attempts to brush Masaomi off until he pulls out a camera, proving he was serious about going to the teachers if he kept harassing Anri. Masaomi later appears to, once again, stop Nasujima from harassing Anri, this time dropping the name Haruna Niekawa to scare him off. Masaomi explains to Anri that Haruna was the previous student that Nasujima was fixated on before she was forced to transfer.
Yellow Scarves ArcEdit
After seeing Anri in the hospital because of the slasher, Masaomi rejoins the Yellow Scarves as their leader. He declares that the Yellow Scarves' current objective is to hunt down the slasher and to search for more info on the Dollars, crushing them as well if the slasher is operating from within the Dollars' ranks.
After musing about his past, Masaomi hears one of his guards interrupt the meeting with the news that someone is spying on them. Masaomi and several other gang members run outside and search for the girl. When she is rescued by the Black Rider, one of the members throws a metal pipe at them, and the girl cuts it in half with a katana, proving herself to be the slasher. Remembering that the Black Rider was at the Dollars meeting, this cements the Yellow Scarves' belief that the Dollars and the slasher are allied with each other.
The next night, Masaomi visits Saki in the hospital to talk to her about recent events as Saki mentions that she sees him from her window all the time. The conversation brings up bad memories, and Masaomi leaves, with Saki cryptically saying she knows he will come back.
Masaomi visits Kyouhei and his crew to talk about how to handle the situation with the Dollars and Yellow Scarves. Kyouhei simply tells Masaomi to follow his gut, but Masaomi refuses to accept such a vague answer. As the conversation gets more heated, Simon attempts to diffuse the situation but is ignored.
Denis gets angry because their talk is scaring the customers, so he throws a knife into the private room, sticking it into the wall, and tells them to stop talking about such a violent topic. Masaomi leaves and reluctantly seeks help from Izaya, who reveals that Mikado is the leader of the Dollars. Masaomi tells his subordinates to stop the attacks on the Dollars, but the attacks only grow worse.
When Horada and his thugs go after Anri, Masaomi grabs her and drags her into an alley to help her escape. He confronts her about being the slasher and working with Mikado, the leader of the Dollars. He accuses her of manipulating him and Mikado, causing Anri slap him in the face and run away. He gets a call from Horada saying that he knows that Mikado is the leader of the Dollars and that he has taken control of the Yellow Scarves. He also tells Masaomi that he is weak and no longer needed before hanging up. Furious with himself and the situation, Masaomi makes the decision to run to the Yellow Scarves headquarters alone to take care of Horada and the gang.
Simon sees Masaomi and notices his grim demeanor. He tries to dissuade Masaomi from doing anything reckless, but Masaomi cheerfully waves and and keeps running. Masaomi confronts Horada at the Yellow Scarves headquarters, where Horada reveals that the only members left in the Yellow Scarves are the former Blue Squares loyal to him. The members of the original Yellow Scarves still loyal to Masaomi have been attacked and hospitalized. Horada throws a crowbar at Masaomi, who takes a hit to the head. Bleeding, he picks it up and defends himself from Horada's attacking thugs. He manages to hold them off while simultaneously advancing toward Horada. Just when Horada is about to shoot Masaomi with his gun, a Yellow Scarves member under Anri's control stops him, stating that 'Mother' wouldn't like it if Masaomi were hurt. Soon after, Anri slashes the door to the hideout with Saika and Mikado rides through on the back of Celty's bike.
With Anri, Mikado, Masaomi, and Celty all in the room, Horada orders the rest of the Yellow Scarves to kill them all, but Kyouhei's voice shouts out, and a large number of Yellow Scarves begin attacking other members. It is revealed that about thirty of the members who showed up that night were actually Dollars members whom Kyouhei and Saburo called in to help. Amidst the chaos, Horada lets slip that he was the one who broke Saki's legs. Masaomi, infuriated, punches Horada in the face before falling down unconscious. Mikado then holds him up and asks him to wake up. He wakes up, telling Mikado that he does not want him to "go to the dark side" before falling into unconsciousness again. Kyouhei tells Mikado to take Masaomi to the hospital, promising to take care of the rest of the former Blue Squares members.Masaomi wakes up in the hospital, and Anri and Mikado are relieved that he is alive. They leave to let Masaomi rest. Later, Saki comes in and tells him that her being kidnapped by the Blue Squares two years prior was part of Izaya's plan and something she had let happen purposefully. The two of them confirm their feelings for each other, and when he is better, they run away together.
Masaomi joins the chatroom as Bacura, giving TarouTanaka subtle hints about his well-being and giving Kanra death threats.
Masaomi and Saki are working as field agents for Izaya, gathering information for him to use as a way to support themselves. Recently, Masaomi and Saki were asked to gather information on Jinnai Yodogiri. Masaomi is suspicious about the job due to the fact that it was given so suddenly and the fact that the area they're supposed to search in is very remote and isolated. Masaomi is also unsettled due to the fact that there aren't any real computers in the town they're heading to and he can't log into the chat room. Saki says that he's become too addicted to the internet and also wonders why Masaomi can't simply just visit them instead of just going on the chatroom. Masaomi replies that he just can't see them because he fears that they won't accept him if he did go back.
Dollars and Blue Squares ArcEdit
After they return from their trip, Kida logs on to the chatroom to catch up but no one is on. He tries to check the archive history but finds it empty as well. He logs back on again the next day and asks Mairu and Kururi for an update on what he missed. The twins are confused as they remember Masaomi being on the day before. Kida is alarmed about this and asks if TarouTanaka was on as well. The twins say yes and Kida immediately makes the assumption that his account was hacked and also has a good idea as to who is responsible.
Masaomi calls Izaya and asks him what he said to Mikado in the chatroom and why he hacked into his account. Izaya taunts Masaomi, asking him why he doesn't just talk to Mikado about it and telling him he is being a coward. The insults hit a little too close to home and Masaomi lashes out at Izaya who promptly hangs up on him, saying he doesn't like being yelled at.
A few hours later, Saki asks Masaomi if he was lonely. Masaomi tries to deny it, saying that he has her. Saki sees through the lie and says that while she can be Masaomi's lover, she can't be his friend in the same way Mikado and Anri can. She says that, from the way he described them, it would be impossible for his friends to abandon him and even if they did, She would be there to help him back up. Saki goes on to say that if Masaomi's friends are in danger, then the only person who can, and should, help them is Masaomi himself. Reinvigorated by Saki's words, Masaomi packs a few changes of clothes and heads out to Ikebukuro to help Mikado.
Masaomi isn't seen until much later after Mikado tried to apologize to Chikage Rokujou. He see's Mikado break down in tears and immediately stops himself from calling out to him. He realizes that, with the way he was right now, he wouldn't want to be seen in that state by Masaomi. Masaomi turns and leaves, deciding to re-introduce himself after Mikado had recovered.
Masaomi learns about Mikado and Aoba going around and expelling dollars members and decides to investigate. Masaomi learns that Mikado was chasing after Ruri Hijiribe's stalker and decides to intervene before he could do anything rash. When he returned to Ikebukuro he says sorry to Shizuo, but Shizuo just pokes him and Masaomi flies in the air but got up back. He chases Mitsukuri after he saves Shizuo from Kisuke's men for answers, but knocks him out before he can say anything.
Later he arrives too late and sees that Mikado has already been beaten severely by Kisuke Adabashi. Masaomi manages to get the jump on Adabashi long enough for Mikado to light him on fire. Masaomi is shocked at the level of cruelty that Mikado had shown and is disturbed at how Mikado can simply smile through it all. He yells at Mikado for what he was doing but Mikado simply brushes him off and walks away.
Masaomi eventually runs into Anri as well but he told her he can't explain things now and tells her to wait but both are worried at Mikado's recent behavior. Masaomi eventually decides to reform the yellow scarves with the sole purpose of bringing Mikado back to his senses as well as to crush the Blue Square remnants that have assimilated into the Dollars.
He calls Koji and tells him to summon the rest of the Yellow Scarves.
Dragon Zombie ArcEdit
Masaomi continues to frequent the chatroom and greets several of the new members that have joined (including Saki who joined at his invitation). He tries to get in contact with Mikado via private chat but Mikado simply replies that he'll be leaving the chatroom and logs off. Later, he enters Russia sushi with a yellow scarf around his neck and asks Kadota for advice.
Kadota's Coma ArcEdit
Continuing from the last arc with Masaomi being in Russia Sushi with Kyouhei, Saburo and Walker. Masaomi asks them to quit the Dollars and join the Yellow Scarves. Kyouhei tells him that he will think about his request, however if they ever became enemies he wouldn't hesitate to fight. Masaomi simply tells him, if that was ever the case, he'd avoid bumping into him at all costs.
When Kyouhei is hit by a car in a hit and run, Masaomi is shocked by the news. He later gathers the most loyal Yellow Scarves members in karaoke bar and plans on starting a war with the Blue Squares again in order to save Mikado. Though the other members did not like the idea, Masaomi had made his mind up. Out of nowhere, Walker enters the room with another member of the Yellow Scarves, Koji. Masaomi then asks Walker why he was there and Walker asks if the Yellow Scarves were behind the hit and run with Kyouhei.
Masaomi senses that Walker had suspected them, with Walker reiterating that he just wants to know if they did or did not. He knew Masaomi would never harm Kadota, but suggested it may have been a member of the Yellow Scarves working behind Masaomi's back. Masaomi tells him, if that were the case, he'd allow Walker for any punishment on his group and Walker leaves. Masaomi then notions to his members the scent of kerosene in the room, alerting everyone had they not been careful with their words, Walker would have set the room alight. Walker re-enters the room, frightening everyone, only to tell Masaomi that Shizuo had been arrested. After the night of the raid Masaomi is worried about the members that could've been attacked by Hoji (A Blue Square member). It was then he decided that he'll do anything in order to turn Mikado back, even if it meant hurting him.
Volume 11 Edit
Chikage challenges Masaomi to a fight, offering to work under Masaomi if he were to lose and vice versa. Masaomi eventually latches onto Chikage, Chikage then jumps across onto a neighboring building in an attempt to ravage Masaomi. He lets go in time, causing Chikage to fall from the parking lot although seemingly fine.
Volume 12 Edit
Immediately after, Izumii arrives with his gang, ready to fight the yellow scarves. Chikage remarks from below telling Masaomi to be prepared, as he will climb back up. Masaomi however is focused on Izumii, who taunts him about the incident involving Saki consequently angering him. He evades Izumii and punches him square in the face, and acquired an arm injury. After inflicting more damage, Izumii takes a few Yellow Scarves members hostage. Yatabe urging Masaomi to run, in which he doesn't. Threatening to kill them, he reveals himself as a member of Dollars. He is saved by Chikage.
Final Curtain Arc Edit
Masaomi confronts Mikado atop the Tokyo Hands building. Mikado and Masaomi struggle for a bit, weapons eventually coming out before ending with Masaomi being shot in the knee by Mikado. Following this, Mikado launches into a long rant, eventually turning the gun on himself. Masaomi is shouting to Mikado the entire time, just before a gunshot rings out over the town. Before the bullet could successfully bury itself into Mikado's skull, Celty who has since recovered her head and memories, stops the bullet with her shadows.
Durarara!! SH Edit
Masaomi is revealed to be working in an unknown business.
Manga, Light Novel and Anime Differences Edit
Masaomi was not present when Mikado first met Shizuo in the manga.
- Main article: Mikado and Masaomi
Masaomi and Mikado have been friends since childhood, and after Masaomi moved to Ikebukuro in middle school and started the Yellow Scarves, he kept in touch with Mikado online. His emails with his old friend back home were a reprieve from his increasingly chaotic daily life, and eventually he invited Mikado to join him in the city. Their relationship becomes strained when Masaomi resumes leadership of the Yellow Scarves and learns his best friend is the leader of the Dollars, but after reconciling and leaving the city, Masaomi stays in touch with Mikado.
- Main article: Masaomi and Anri
Masaomi and Anri are close friends who met in their first year of high school. With Mikado, they are known as the 'Raira Trio.' Masaomi keeps a friendly, flirtatious attitude up around Anri, but when she is hospitalized, he returns to the Yellow Scarves to find the slasher.
- Main article: Masaomi and Saki
Saki initially approached and dated Masaomi on orders from Izaya. Though he was unnerved by her blind faith in Izaya, he wanted to help her move on from him. When she was kidnapped by the Blue Squares, Masaomi tried to save her alone, but he was terrified of what the gang would do and was unable to move forward. After Saki woke up in the hospital, out of guilt he could not bring himself to visit her, and she waited in the hospital for two years. He visits her once when his friends were in the hospital after the slasher attacks, but unable to stand her continued faith in Izaya, he distances himself from her again. After confronting his own past, he moves forward with Saki, leaving the city with her.
- Main article: Kyouhei Kadota
Kyouhei and his gang treat Masaomi as a friend. Though they were members of rival gangs when they met, Masaomi is grateful toward Kyouhei and his friends for saving Saki when he could not. He also feels guilt around them, as they are the few who know about his inability to save her and his reservations about visiting her in the hospital. They find themselves on opposing sides again when the Yellow Scarves search for the slasher inside the Dollars, but they offer him frank advice on how to move forward.
- Main article: Izaya Orihara
When they first met through Saki, Masaomi put faith in Izaya, whose predictions about rival gangs always proved true. Masaomi used this knowledge to strengthen and expand the Yellow Scarves. When Saki was kidnapped by the Blue Squares, Masaomi reached out for help and Izaya abandoned them. Izaya came to the hospital when Saki was still in a coma and told Masaomi that his guilt over being unable to save her would eat at him and shape his future, and he would never be able to run from her. When Mikado moved to Ikebukuro, Masaomi told him to watch out for Izaya Orihara and never cross him. Izaya and Masaomi interact in a joking manner that barely masks Masaomi's deep animosity for him. Especially online, where Bakyura 'jokingly' goes out of his way to harass Kanra. However, both parties know it is truly how Masaomi feels.
Ran Izumii Edit
- Main article: Ran Izumii
As the man who kidnapped and crippled Saki, Masaomi hates him.
- Main article: Horada
Horada is a member of the Blue Squares that implemented himself into the Yellow Scarves to get revenge on Masaomi. Horada attempted to frame Masaomi for the attacks on the Dollars, especially the shooting of Shizuo. Masaomi was angry with Horada for chasing Anri. Horada launched a coup against Masaomi and attempted to shoot him, but Kyouhei and Anri intervened.
Koji Yatabe Edit
- Main article: Koji Yatabe
Koji is a member of the Yellow Scarves and Masaomi's second-in-command. They have been good friends since middle school.
- His favorite subject is English.
- His least favorite subject is history.
- His favorite quote is "Love is a leveler."
- He likes eating meals with girls and dislikes eating when he is only with males.
- In volume 4 of the Light Novels, Masaomi starts singing the "tsun tsundere tsun" song as a joke on the chatroom upon Izaya calling him a tsundere and cites Sakurashin town as the song's origin. Both the song and the town he mentions come from the manga Yozakura Quartet (a manga series by Suzuhito Yasuda, artist for Durarara!!), which implies that Durarara!! also takes place within the same universe as the aforementioned manga series.
- He sang "Linda Linda" in the rapping CD.
- His birthday, June 19, is the "Day of Romance" in Japan.
- According to the official DVD 2 released character profile card, his hobby is picking up girls.