Childhood friend of Mikado Ryugami, he is the outgoing and active counterpart to Mikado's sheltered lifestyle. Very at home in the city of Tokyo, he serves as a guide to Mikado.
Masaomi considers Mikado to be an old, close friend
Masaomi Kida is a childhood friend of Mikado Ryugamine as the two grew up together as kids. Some time before the series started, he moved to Ikebukuro to go to middle school there. However, while he was there, he got caught up in the color gang wars and created a color gang called the Yellow Scarves. Things went well for a time until he was introduced to Saki Mikajima and Izaya Orihara. Distrustful of Izaya, he found that Izaya was a helpful tactician with his gang. But due to unforeseen circumstances, Saki was attacked by the Blue Squares and after that event Masaomi disbanded the Scarves. He convinced Mikado, his only friend, to attend high school with him as he accepts this invitation.
Due to his involvement in gangs, Masaomi knows every strong figure in Ikebukuro who are not to be crossed for any reason.
In the start of the series, Masaomi acts extremely chipper and light hearted about many things in his life. He constantly attempts to woo the different girls at his school but always fails miserably. It is shown that he cares a great deal for his friend Mikado and Anri Sonohara, who he met through Mikado. Even when the three are together, he always acts carefree and that there is nothing wrong with anything in the world. He sees the relationship he has with Anri and Mikado as a three way love triangle in which he cares for Anri deeply and will do anything for her.
In reality, he feels alone a lot of the time and feels depressed about the way life has turned out for him. He tries to protect his friends from the darkness of Ikebukuro but feels helpless when they get drawn into things as well. Masaomi also feels guilt over the attack on his girlfriend Saki that took place around a year ago as a result of the gang violence and what little he did to prevent the attack. He harbors a deep hatred for Izaya too since he knows he is behind anything that goes on in Ikebukuro.
Major Story Arcs
Welcome to Ikebukuro
Masaomi gives Mikado a tour of Ikebukuro
Masaomi is the first person to welcome Mikado to his move to Ikebukuro. On the first night there, he shows him around the town and highlights different venues and shops. He also introduces Mikado to Kadota, Walker, Erika, and Saburo; four friends of his he has known for a while now. They also pass by Simon Brezhnev, the local owner of the sushi bar. Masaomi warns Mikado that the streets can be dangerous at times. Even though the color gangs have disappeared, there are always rumors about the Dollars in the city and what they'll do. Masaomi informs Mikado that there are two people he should never cross: Izaya Orihara and Shizuo Heiwajima. Mikado wonders who Shizuo is as they see a vending machine flying in the distance, Masaomi indicating that was the work of Shizuo. The two get a glimpse of the Headless Rider as she runs down the road, Masaomi explaining the urban legend behind the rider.
School starts for the two as they go to Raira High School for their academic career. They find themselves in separate classes but often walk to school and go home together. When Mikado becomes class representative with Anri, she becomes a part of the group that they hang out with. This escalates after Mikado asks about the Dollars and the two friends encounter Anri getting bullied by a group of ganguros that go to their school and a so-called member of the Dollars. Izaya offers to help as he assists the boys in helping Anri and teaching the bullies some manners. Afterwards, when Shizuo is jumped by a bunch of gang members, Mikado leaves Masaomi behind to get Anri out of there.
Masaomi stills acts like a clown especially when he helps Anri avoid a perverted teacher of theirs. It is at this time he admits he feels alone and he must protect Mikado from the darkness of the city. While he walks around town, he almost gets jumped by a group from the Yellow Scarves but is helped out of the situation by Mikado who are able to escape thanks to Celty. As time goes on and the dilemma over Celty's head escalates, Masaomi is not involved as he is too busy trying to figure out who in the school is a member of the Dollars. Masaomi also admits to avoiding Saki as long as he can.
After the flash mob meeting of the Dollars, six months pass as Ikebukuro is becoming the home to the Yellow Scarves once more. A group of Scarves approach Masaomi with an offer about something but he declines. It is at this time that the Slasher attacks start to occur around the city where people are attacked but not killed. Masaomi is concerned about Anri since one of the Slasher attacks almost got to her since the assailant attacks the ganguro bullies from earlier.
Masaomi restarts the Yellow Scarves.
Things heat up when Haruna Niekawa attacks Anri who admits to being the Slasher. Even though Anri defeats her, she is still badly wounded and taken to the hospital. Masaomi and Mikado visit her as Masaomi vows revenge for Anri. He goes to the docks where the Yellow Scarves are based out of and announces his plans to lead the Yellow Scarves once more, indicating that he was the original leader before they disbanded. He says that he is doing this to get the Slashers for what they did to Anri and will take down the Dollars too if they have a part in this. What Masaomi doesn't know is that Anri is actually the mother of the Slashers.
In the ensuing months, Masaomi works with the Yellow Scarves to figure out who leads the Dollars and the Slashers and how to get back at the latter. He hates working with Horada who is extremely violent and wants to beat up random people even though no one knows who anyone in the Dollars is. It is revealed through a flashback that he came to know and date Saki through Izaya and Saki was kidnapped by their rival gang the Blue Squares. Izumii, their leader, broke both her legs and told Masaomi to come and face off to save her but he froze up. Kadota and his group leave the Squares and save Saki, never telling her what happened with Masaomi. Saki was able to testify though against Izumii as he went to jail for aggravated assault and broke up the Blue Squares. Masaomi disbanded the Yellow Scarves as a result of this before going to high school.
Masaomi tries to gather information and clues about the groups as he tells everyone to keep things on the down low. One of his gang members tells him the rumors about how Celty may be the Slasher since she is also known as a member of the Dollars. Masaomi tries to investigate but when Anri sneaks in to their base to find out whats wrong with Masaomi, she freaks out and leaves. Almost getting caught, she is saved by Celty and uses her blade to evade attack. Masaomi is now 100% certain that the Slashers are members of the Dollars. He goes to Izaya reluctantly to find out who the leader of the Dollars is as he finds out it is Mikado.
Masaomi confronts Anri about her role as the Slasher
Unable to process all the information, Masaomi tells everyone to stay put while he figures out what to do. Horada becomes impatient and begins to start attacks on random people in hopes of hitting the Dollars. Anri is able to stop some of the attacks since she has control over the Slasher victims and is able to rescue some people. However, she was spotted a few times as they tell Masaomi about the Slasher being a girl with glasses, a Raira uniform, and big boobs. Masaomi pieces together that Anri is the Slasher and confronts her after the Dollars help her escape from the Scarves. He accuses her of being a whore and gets slapped before she runs off.
Masaomi continues to figure out what all this means and makes brash assumptions about Mikado and Anri that he is disgusted by. Horada calls him to tell him he has been ejects from the Scarves and now he is an enemy. They also know Mikado is the leader of the Dollars and begin to plot to attack and kill both of them. Horada goes as far as to gun down Shizuo and blame it on Masaomi. Masaomi knows that he can stop this and goes to the hideout but is stopped by Simon. Simon asks him to reconsider going in to the base to die but Masaomi explains its the only way.
At the base, Masaomi confronts Horada and puts together that he was Izumii's partner and that most of the new members of the Scarves were also Squares. Masaomi fights his way through the gang with a crowbar and almost gets to Horada but is knocked out first. Before Horada can kill him, Anri breaks into the base with Celty and Mikado right behind her. They look to be cornered but Kadota emerges and begins a counter attacked as the Dollars had infiltrated the Scarves since no one knows who is in the Dollars. Mikado and Anri are able to get Masaomi to the hospital with the help of Saburo, Erika, and Walker as Celty, Shizuo, and Kinnosuke Kuzuhara take down Horada.
When he wakes up in the hospital, Saki meets him to reveal that she was caught intentionally by the Blue Squares and feigned being crippled because Izaya told her too. Masaomi knew the whole time as he vows to leave Ikebukuro with her once they are better. He fulfills this promise as Mikado and Anri worry about him, Mikado knowing he'll be back soon since Masaomi uses the online alias Bakyura on the Dollars website as he sends him a message about the square root of three, something Mikado and said to him earlier in the series.
While in middle school, Kida founded the gang 'Yellow Scarves' and fell in love with a girl named Saki while he forged a friendly relationship with Orihara Izaya. However, he found out that his involvement with Saki and his dealings with Izaya came with a price when the Blue Squares gang kidnapped Saki and broke her legs while he was powerless to do anything about it. As a result, he has been reluctant to return to his former life, but with the news that Anri got hurt during the Slasher incident he feels it is necessary to become the leader of the Yellow Scarves once again.