Durarara!! : Season 1

Mikado Ryūgamine leaves his country home to attend high school in Ikebukuro, Tokyo with his childhood friend Masaomi Kida. Three people chat online about current events in Ikebukuro. As Mikado and Kida wander around the district, Mikado meets four of Kida's friends: Walker Yumasaki, Erika Karisawa, Saburo Togusa, and Kyohei Kadota. Elsewhere, a trio of men confirm that their target is a teenage girl. In the chatroom, they discuss the recent mass suicides. A man approaches the girl and leads her

Mikado and Masaomi begin the school year in separate classes. In Masaomi's class is the girl who was kidnapped before, Rio Kamichika, and her background story is revealed, including her encounter with the headless rider.

Anri Sonohara, a classmate of Mikado's become class representative along him. While goofing off with Kida, Mikado spots Anri in trouble and decides to lend a hand to her and coincidentally, getting himself into a clash involving the dangerous Shizuo Heiwajima and his sworn enemy, the elusive Izaya Orihara.

Shinra Kishitani, an unlicensed underground doctor, talks to the headless woman, whose name is revealed to be Celty Sturluson, about her day using a chat room. That morning, Celty learned from Izaya that an old street artist saw a dullahan missing its head. Celty quickly goes to find the man, but cannot find him. Shizuo knows where the artist is and helps her talk to him. However, they find that the artist could not draw the dullahan's head. Shinra tells Celty to give up looking for her head so

While hanging out with Anri, Mikado and Kida learn about her worries for her missing friend and try to cheer her up. Later the duo gets themselves in trouble when they are cornered by a gang of thugs.

The Dollars gang figures that a foreigner friend of theirs was captured by the manhunters and search through Ikebukuro determined to rescue him.

Shizou has been very angry and destroys everything around him. Just as he recalls how he started doing that, his past involving the secret of his limitless strength, his relationship with Shinra as well as his encounter and vendetta over Izaya Orihara is revealed.

After losing contact with his brother Seiji, Namie Yagiri enlists Izaya's help to find him. While roaming through Ikebukuro, Seiji and Mika Harima stumble unto Shizuo and Celty and a heated pursue begins after Celty figures that the head attached to Mika's body is actually hers.

After losing contact with her brother Seiji, Namie Yagiri enlists Izaya's help to find him. While roaming through Ikebukuro, Seiji and Mika Harima stumble onto Shizuo and Celty and a heated pursuit begins after Celty figures that the head attached to Mika's body is actually hers.

Mikado runs away with Mika and shelters her into his apartment. However, in the following day, he is approached by Celty and Izaya, and after telling her secret to him, Celty convinces Mikado to help her find Mika. Unfortunately, Mikado is cornered by some Yagiri Pharmacy workers who question him on Mika's whereabouts. In order to save Mika, Mikado reveals to Izaya and Celty his secret.

Mikado phones Namie proposing a deal, Namie attends with some followers around. Mikado claims he has Mika and demands the "truth" behind what she has done to Mika, she does (unknown to the viewer) while Kadota brings Mika to Celty at the roof of a building nearby Mikado and Namie. Mikado disguisted by the truth asks Namie to turn herself in, she thinking of Mikado's thoughts as nonsense orders her henchmen to move, however Mikado revealing himself as the leader of the Dollars sends

It is discovered that Harima Mika is actually alive, and that Celty's head is being held by Yagiri Pharmacy. Shinra had known about it, and kept the secret from Celty for the fear of losing her because of her head's will.

Six months had passed since the Dollars meeting at Ikebukuro. Since then, the police starts chasing Celty tirelessly through the city, leaded by Kinnosuke Kuzuhara, a reckless police biker specially assigned to aprehend her. After losing their tail, Celty is asked by Shinra to pick his father Shingen who just arrived at Japan. Meanwhile, another urban legend, the mysterious assailant known as "The Slasher" is attracting the media's attention as his/her identity is a mystery, and just when Anri

Anri and several others are attacked by the slasher. Each night someone is attacked, someone called Sinsong appears on the web, writing mysterious messages. "Today. Cut. Did Cut. More. Stronger. Love. Wish. Wish. Is. Want." Mikado is bothered by the rumors that the Slasher attacks are being perpetrated by the Dollars, and asks Celty for help. Celty eventually learns from Shinra that his father Shingen previously acquired a sword called Saika to separate the link between Celty's head from her

A journalist named Shuji Niekawa is beaten up by Shizuo six months ago while trying to research who is the strongest person in Ikebukuro. As he goes around interviewing Simon, Izaya and Celty, Niekawa narrates his feelings on his latest work and the regret of not able to bond with his distant daughter, Haruna. After heading back home from a long day of work, Niekawa is attacked by the slasher who stabs him with a kitchen knife. After he survives the attack with no memory of the incident and

Just as Shizou defeats Shuji, Celty takes the knife he drops and shows it to Shinra claiming that it could be Saika. Haruna Niekawa the daughter of Shuji comes to visit Anri to discuss about Nasujima, the teacher who harrases Anri. Shinra and Celty discussing about Saika, discover that Saika loves humans so much that it demonstrates her love via actions manipulating her host. They also find out multiple Saikas in the chat room as they find out that Saika slashes humans just as it leaves her

Sonohara pokes Niekawa with Saika, and shows her a flashback of how she became its wielder. Sonohara's father was an antiquities dealer, and constantly beat up her and her family. Her mother then got possessed by Saika, killed her father, and committed suicide. Sonohara then grabs the cursed blade, and becomes its wielder. Meanwhile, Shizuo beats up Niekawa's "Saika children," flashing back to his past. Sonohara then assimilates Niekawa's Saika, and as a result takes control of all of the Saikas

While Ryugamine and Kida are walking Sonahara from the hospital after she had recovered, Kida gets a phone call from the Yellow Scarves and he runs off, Ryugamine and Sonahara not knowing anything. Kida, resuming his lead role of the Yellow Scarves, retells his past about him and a girl named Saki who is left in Ikebukoro hospital. While he was in the Yellow Scarves, he met her along with Izaya Orihara who claimed to be her guardian. Whenever Kida was in trouble or needed help with his decisions

Anri Sonohara runs away from the Yellow Scarves. She hides in a dark alley and is scared of what will happen if Kida finds out her identity. The scene flashes back to when Anri was fetched out of the hospital by Mikado and Kida. Anri is puzzled over Kida's strange behaviour and worries about causing a gang war over Saika. This prompts her to ask her 'children' in Yellow Scarves who their leader is, not believing it when told it was Kida and decides to investigate. The scene comes back to when

Kida Masaomi looks into matters concerning the leader of the Dollars. He confronts Kyohei Kadota, a former Blue Squares member, about who might know something about this. Walker and Erika are there as well and they lecture Kida about forgetting that the blue squares ever existed since they hurt Saki Mikajima, Kida's former lover. They tell Kida to move on with his life and to forget that incident with Saki ever happened. Kadota gives Kida semi-useful information, but it still isn't enough. Anri

Mikado visits his injured classmate and Dollars member at the hospital instead of Kida since he backed out. His classmate tells him that he is going to quit the Dollars because he believes it is unsafe now. He then asks Mikado if he is part of the Dollars but he hesitates and says no. Mikado begins to worry about the Dollars and how the Yellow Scarves are threatening them. More Dollars members also begin to quit over the website. Celty discusses with Shinra of how Mikado, Sonahara and Kida don't

Sonohara is being taken away by the Yellow Scarves gang but Mikado asks the Dollars to help her. Izaya sees this too and decides to observe from afar. She escapes with the help of various members of the Dollars (to which she is unaware), but is found again until Kida grabs her hand and secretly helps her escape from them. He then asks her what she wants from all this and accuses her of tricking him while sucking up to Mikado; disgusted by these accusations, Anri slaps him and walks away. Kida

Kida learns that he has been marooned by the Yellow Scarves. Celty confronts Mikado and reveals the truth about Kida and Sonohara. Meanwhile, Shizuo knocks on Shinra's door, heavily wounded by the gun shots. Shinra gives him medical treatment while Shizuo swears to kill Kida and the Yellow Scarves for shooting him. Sonohara then runs away, wanting to warn Kida. Kida returns to the Yellow Scarves hideout and learns that the Blue Squares have taken over Yellow Scarves from the inside. He then

Half of the Blue Squares turned Yellow Scarves members counter attack Horoda as they reveal themselves as Kadota and 30 other of his friends. Kida is then taken to the hospital by Mikado and Anri while Celty chases Horoda who managed to escape the warehouse. While running away with the rest of his main gang, they encounter Shizuo who hurls a big sign post and chops the roof of their car. Celty then stops knowing that they encountered Shizuo but the Ikebukuro police then manage to eventually