Mikado, a young man longing for something unusual in his life, moves to Ikebukuro at the invitation of his childhood friend Masaomi. Arriving in Tokyo, he begins his new life as a high school student, awed and mesmerized by the new world around him.

It is the Entrance Ceremony at Raira Academy, and the auditorium swells with a varied mix of emotions emitted from the students. Amidst all this is Rio Kamichika: a girl with a notably dark vibe following her.

Masaomi Kida is out about town, fervently trying to pick up girls, while Mikado tags along, feeling a bit confused and bewildered. Various people intermingle throughout Ikebukuro as rumors of the “Dollars” spread.

People throughout the city speak of an urban legend known as the “Headless Rider”. A surprising number of people have personally witnessed it speeding down the streets on a jet-black motorbike with no license plate.

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.

Shizuo Heiwajima, also known as “the strongest man in Ikebukuro”, is a man who definitely relishes that title. Though he carries with him a high esteem, something is amiss. Lately he has been extremely short-tempered and does not know why.

Celty runs away from home after arguing with Shinra, and an exchange student asks people to write what they're looking for in a notebook she carries.

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.

Anri's missing friend, the Dullahan, the girl with the scar on her neck, Yagiri Pharmaceuticals, the kidnappings, and the Dollars... little by little, the pieces begin to fall into place.

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.

Half a year has passed since the Dollars meeting and Ikebukuro seems to have returned to normal. But underground, the Yellow Scarves and the Slasher are becoming increasingly active. Darkness approaches, ready to destroy the days of peace.

Anri is attacked by the Slasher. The same night, the user Saika appears in the chatroom, and posts a puzzling message. Mikado, worried about rumors that the Slashers are the Dollars, decides to cooperate with Celty.

Magazine Journalist Shuji Niekawa’s unbridled passion is raging. A Russian who runs a sushi shop, the Awakusu organization, an Information Broker, the Headless Rider... He investigates the supposedly strongest man in Ikebukuro: Shizuo Heiwajima.

Anri is targeted by the Slasher, but Kyohei’s gang moves to rescue her. Shizuo and Celty join in, and after defeating the Slasher, reveal his true identity. However, this moment of relief doesn’t last as Celty reads what has been posted in the chatroom.

As Anri faces off against Haruna, truths about her past are revealed. Elsewhere, Shizuo fights an unending battle against the Slashers in South Ikebukuro Park. As he defeats them one after another, his expression starts to take on a hint of joy.

Civil unrest begins to descend upon Ikebukuro. Masaomi finds himself in an abandoned building, depressed, thinking about his past: how he ended up back there, and how a girl still waits for him at a hospital.

Anri notices something is wrong with Masaomi, and takes action to find out what it is. Elsewhere, a gang-war breaks out between the Yellow Scarves and the Dollars over the Slasher’s identity. The standoff grows as Mikado’s desire to stop it is ignored.

After doing some investigating, Masaomi starts to suspect that the remnants of the Blue Squares, a gang that he once fought, have slipped into the Dollars. He decides to visit Kyohei’s gang to learn the truth.

Despite Mikado’s orders, the Yellow Scarves hunt down members of the Dollars. Mikado begins to question whether the existence of the Dollars is worth such a sacrifice. Anri tries to put a stop to the gang war, but ends up making the situation worse...

The Dollars are enraged at the Yellow Scarves’ actions. The Yellow Scarves learn that Anri is the girl who escaped from their hideout during the night of the meeting, and track her down. However, an unexpected group of people steps in to save her...

A gunshot resounds from an alley, echoed by a phone call for Masaomi. Mikado rides with Celty, and Anri learns the truth. Their hearts are filled with trust, doubt, and unease. Everything rushes toward a conclusion, and Izaya enjoys the chaos.

Filled with unwavering determination, Masaomi enters the abandoned factory, and encounters the unexpected. At last: Masaomi, Mikado, and Anri face off. Although each of them carries inexpressible feelings, they eventually find an answer...

A bonus episode taking place between the two halves. Glowing discs are spotted throughout Ikebukuro. Meanwhile, confusion erupts when multiple criminal groups lose track of identical bags simultaneously. Also, Anri is wearing cat ears and a Yukata, Mikado has rabbit ears, and Masaomi is a harlequin. Walker believes that reality has stolen a story he is working on.

Yuuhei hosts a show searching for the loveliest couple in Ikebukuro, the winner of which gets to appear in one of his movies. As Mikado and Anri go to the movies together, hoping to clear everything up between them, they are interviewed by Yuuhei. A guy with a knife tries to attack Yuuhei, but he is stopped by Shizuo, who is also being hounded by Izaya's sisters wanting to meet Yuuhei. Shizuo then encounters Izaya, who arranged for the attack, and enters a huge fight with him which escalates throughout Ikebukuro, prompting Celty to move into action. As the fighting escalates, several smaller fights break out, forcing Celty to use her powers to stop everyone. This is Episode 25 of Season 1.

Half a year has passed. The city of Ikebukuro seemingly remains unchanged, but foreign elements are slipping in, the serial killer known as “Hollywood” being one of them. The fuse to a new series of events begins to smolder!

Due to her appearance on TV, Celty Sturluson has gained even more attention and 10 million yen is being offered to uncover her identity. Meanwhile, Raira Academy welcomes its new students, which includes Mairu and Kuriri, Izaya Orihara’s sisters.

The idol Ruri Hijiribe and actor Yuhei Hanejima; two people who, despite being hugely popular, remain a mystery. A chance meeting gives them reason to reveal their secrets to one another. Meanwhile, the various situations in Ikebukuro begin to intersect.

While transporting some mysterious luggage, Celty attempts to escape the biker gangs out to claim the 10 million bounty that’s been placed on her. Caught up in the chaos, Mairu and Kururi join with Kyohei and the others.

With the uproar over the bounty settled, the city appears to be peaceful. However, the sparks of a new uproar begin to light, one after another. The womanizing leader of the Toramaru gang visits Shizuo, and Celty receives a request from the Awakusu…

A sudden attack strikes Celty. Shinra waits at home for her return, unaware of what’s happened, and is visited by Shizuo, who brings along the mysterious young girl. Mikado hears of a bad rumor about the Dollars and starts trying to figure out the truth.

Two killers in the Russian wilderness discuss the fugitives that have violated their unwritten law. After fleeing the company, Varona and Sloan act as hitmen in Japan. Dennis and Simon watch on as Egor, the “Philosophical Killing Machine” gives chase.

Masaomi contemplates friendship as he travels far from Ikebukuro. Mikado receives an unexpected visit from Aoba. Akane explains the real intention behind her attempt to kill Shizuo. And as Toramaru retaliates against the Dollars, Chikage confronts…

Aoba continues to urge Mikado to become the leader of the Blue Squares. Varona and Sloan, meanwhile, maintain their pursuit of Celty as the Awakusu group searches for both Akane and Shizuo.

Akane grew up loved by her family, wanting nothing. When she learned the truth behind the family business, it was Izaya that reached out to her. In the present day, the conflict intensifies between the Dollars and Toramaru, as Kadota and Chikage face off.

As Izaya’s scheme exposes Chikage’s girlfriend to danger, Mikado attempts to stop the cruel reality caused by a runaway Dollars. Meanwhile, Akane returns home with Celty, but the conflict over Akane seems destined to converge…

The flashpoints that had been smoldering in several places unleash major mayhem, swallowing the city of Ikebukuro. In this mayhem, Mikado’s answer is given.

With news of Izaya's hospitalization quickly spreading, the information broker is filled with anticipation and excitement about which of his many enemies will make a move on his life.

Namie is keeping a close eye on Seiji as he and Mika go on a date.

The Awakusu Group executive Mizuki Akabayashi, nicknamed the “Red Devil of Awakusu,” hates drugs and keeps a vigilant eye on the trends in the city of Ikebukuro. The reason why he hates drugs goes back six years to the night of a fateful encounter.

One night, Mikado Ryuugamine accepts an invitation to Shinra Kishitani's apartment, eager to talk to Celty as quite some time has passed since the two last spoke. But, much to his astonishment, he finds that a large group of Ikebukuro's finest has gathered there for a hot pot party.

Already confused with the current situation, Mikado is further surprised to see that his friend and fellow Raira Academy student Anri Sonohara is there as well. As the two decide to take a seat together, a few members of the group begin reminiscing over events from days past: Mikado recalls an adventure from his childhood with Masaomi Kida, Anri explains how she came to be friends with Mika Harima, and Shizuo Heiwajima tells of his first meeting with Tom Tanaka.

Rumors spread about “Ikebukuro’s most dangerous man,” claiming things like, “He’s injured. He has a girlfriend. He has a child.” After her defeat by Shizuo, Varona has lost her sense of purpose. At Dennis’ suggestion, she…

It’s summer, and Anri has begun to worry about Mikado. The popular idol Ruri has been plagued by a malicious stalker. It seems that stalker is in the Dollars. In an attempt to obtain information, Yuhei and Ruri visit Shizuo...

He was in love with Ruri Hijiribe. That was the reason why he became a stalker and loved her so intensely that he wanted to destroy her soul. All the suffering Ruri had gone through, and the reason for the killer, Hollywood, will be revealed.

Everyone involved with Ruri is becoming the target of the stalker. Shizuo and Masaomi find themselves caught up in the action and encounter a member of Blue Square in the midst of it. With Anri in imminent danger, Masaomi seeks out the truth.

Amphisbaena runs an underground casino, and Heaven’s Slave, a gang of drug dealers. Even then, no one can figure out who these two groups really are. The Awakusu Group hires Izaya to do some digging, but...

Using a number of pseudonyms, Izaya has continued to cause an uproar from behind the scenes. One of these pseudonyms is a story that goes back 12 years ago, from the time he was a middle school student along with Shinra.

Various people begin to move around the Dollars. Learning of Mikado’s current situation, Masaomi revives the Yellow Scarves and in his determination to crush the Dollars, approaches Kyohei. Meanwhile, we learn more of Aoba’s history with his brother.

Kadota was in a hit-and-run and the resulting rumors have Saburo and Walker taking action. In an effort to get information on the Dollars, Shuji Niekawa contacts Haruya Shiki. Meanwhile, Akabayashi follows up with Izaya on his investigation of Mikado.

Advancing the internal purge of the Dollars, Mikado tries to realize his ideal, which is leading to a clash with the Yellow Scarves. Various incidents are further entangled as another uproar occurs in Ikebukuro, and the story deepens into further chaos!

In the city of Ikebukuro, something else is beginning to move. Everyone that has gathered in Celty’s apartment discuss how to deal with the problems they’re each facing.

Anri seeks out Erika at the hospital, but they have a few unexpected encounters before they can talk. Meanwhile, other women throughout the city begin to take action.

By one girl’s hand, the existence of the head is made known to the public. In response to the news, Mikado makes a phone call. Meanwhile, Haruna makes a proposal to Anri…

In spite of the mayhem that has been taking place in Ikebukuro, Shinra Kishitani and Celty Sturluson have decided to go on a short trip. Excited to finally be going out with the one he loves, the underground doctor makes it his priority to give Celty his undivided attention, even if it means rejecting phone calls from his good friend Izaya Orihara.

However, despite his hopes of having a peaceful holiday, Ikebukuro's various residents continue trying to reach him. Furthermore, just as Shinra begins to enjoy reminiscing about old memories on a carriage ride together with his beloved, Celty starts to notice a strange presence...

Chikage approaches the Yellow Scarves with a choice, “Have your gang taken over, or have it destroyed.” While Masaomi decides how to respond to this, Anri learns more about Saika and must make a decision of her own.

Kasane’s unexpected visit to Shinra and Celty sparks a chase across the city. Meanwhile, Masaomi and Chikage’s fight has been interrupted by Izumii, who’s looking to settle matters with Masomi.

Izaya is overjoyed at Mikado’s behavior, which has greatly exceeded his expectations, and grows more excited at the future uproar he is ushering in. Masaomi and Chikage talk through things, while Saki and Anri break the ice.

Namie has flooded the chat room with messages calling out Mikado and demanding he take responsibility for the situation she claims he’s created. Meanwhile, Shooter and Shizuo race to Celty and a confrontation with Kasane and Seitaro.

Izaya and Shizuo prepare to face off as the city fills with a mob possessed by Saika.

The number of Saika possessed people continues to increase as they fill the area around Russia Sushi. Anri heads to visit Celty and the Blue Square prepare to confront Chikage, all while Izaya and Shizuo fight to the death.

Anri opens up to Kadota and the others about Saika; meanwhile, Erika discovers that the Saika zombies are after Mikado and Kasane.

Above the confusion of the city below, Mikado and Masaomi finally reunite. Masaomi frantically attempts to persuade his friend, but… Meanwhile, Shinra continues after Celty and encounters Kasane, who tells him the reason he was abducted.

A boy who yearned for the extraordinary, and the twisted love story that swallowed up too many people, finally draws to the end of their performance!

The episode revolves around the man with "the worst luck in Ikebukuro," Shizuo Heiwajima, and another blonde-haired, sunglasses-wearing man wearing a bartender outfit named Shidzuo Nobusuma. Shidzuo is a young hoodlum. As the two men's fates are entangled, a new legend is born on the streets of Ikebukuro.