Durarara is an avant-garde anime series released in 2010 by Aniplex, set in the enchanting and electric world of Ikebukuro, Tokyo. The series, based on the light novel authored by Ryohgo Narita, is known for its dense narrative arc, profoundly diverse line-up of characters, and slick blend of multiple storytelling techniques.

Central to Durarara is a slew of exciting characters who carry their own personal quirks, hidden stories, and unpredictable dispositions. Mikado Ryuugamine, a seemingly ordinary middle-school student from a suburban area, moves to Ikebukuro at the persuasion of his childhood friend, Masaomi Kida. He is fascinated with life in the city, but his fairytale fantasies of city life shatter as he starts to experience the lurking peril underneath the city’s appealing façade.

Then there's Celty Sturluson, one of the most interesting figures in the series. She is a Dullahan—a headless rider from Irish folklore—who roams the city in her black motorcycle that curiously emanates an eerie night sound similar to that of a mystic horse. The headless spirit is in a never-ending search for her missing head.

Next is Shizuo Heiwajima, a near indestructible hot-headed bartender juxtaposed with Izaya Orihara, a mischievous information broker. Mingle with them teenagers, gangs, color-coded factions, a mysterious pharmaceutical company, and an urban legend of a black rider; Ikebukuro becomes a divisively charming urban narrative of myth and reality, ordinary and extraordinary.

Durarara with its unpredictable narrative has wisely managed to weave slices of life with supernatural elements while grounding the story in an urban setting. It keeps viewers on their toes as the story can smoothly transition from light-hearted banter in a classroom to a supernatural event occurring in a dark alley.

The story thrives on ambience. Notably, Ikebukuro serves as more than a mere backdrop. From the hustle-bustle of the cityscape to the dim glowing lights in the dark alleyways, the local eateries and the rich nightlife, Ikebukuro is personified and becomes a living, breathing character within the series. The city's vibe ensnares the viewer; the array of characters, each with their own storyline, adds up to the city’s allure.

Durarara makes remarkable use of different storytelling techniques. Switching between narratives of different characters—a device known as "Rashomon Effect" following Kurosawa's film Rashomon—the series adds multiple layers of depth to the storyline. Each character delivers their own coloured version of the same events, instilling intrigue while pushing the viewer to piece together the puzzle until the final picture emerges.

On the thematic front, Durarara is a clever mix of reality and mythology, offering a thorough exploration of the human psyche while commenting on subjects relating to identity, power dynamics, and urban legends. It also incorporates a touch of internet culture, with chatrooms serving as an essential plot-driving device—an unusual but certainly refreshing narrative choice.

The richly layered narrative is accompanied by a sharp visual style. The animation is fluid and fitting of the story's gritty urban aesthetic. The kinetic energy of Ikebukuro and the surreal moments are captured with well-choreographed action sequences and stylised visual imagery. Moreover, the soundtrack is used superbly, capturing the distinct character of the city with an eclectic mix of jazz, punk, and pop.

Moreover, the pacing of the series is deliberate and each reveal in the story feels like a reward for the viewer's patience. Each thread unravels like a cliff hanger, making each episode a compelling watch.

While Durarara is quite a riddle to solve, it can take a while to get used to the series' eclectic tone. The sheer number of characters and plot threads might seem a bit overwhelming initially. But once viewers get past the early hump, they'll find themselves pulled into an immersive world that’s equal parts quirky, suspenseful, and deeply engaging.

In conclusion, Durarara from Aniplex presents a distinctive blend of urban life, mystery, mythology, and character-driven narratives. Its audacious storytelling, engaging characters, and a uniquely woven narrative platform make it a remarkable series that offers an unusual yet enthralling viewing experience. With its stylish presentation and memorable characters, Durarara stands as a testament to the sheer imaginative power of anime storytelling.