A powerful information broker operating out of Shinjuku. A beautiful, slender young man who belongs to neither good nor evil; his principles are always mysterious. His hobby is human observation—an eccentricity stemming from his unique philosophy: "I love humans."

He carries a flick-blade and is skilled in parkour. As one of the most knowledgeable people in the series, he covers all of Ikebukuro's information and human relationships. Online, he uses multiple handles like the female persona "Kanra" and hosts the chat room where major characters gather.

While he loathes non-human entities and showers them with irony, he exceptionally feels neither hostility nor affection for Celty. He has been at loggerheads with Shizuo Heiwajima since high school, hating him enough to try and kill him on sight, though this is also a contradiction hidden within his "love for humanity." Shinra Kishitani is his only true friend. While he is jerked around by his intense sisters, Kururi and Mairu, he shows a clumsy side that tries to protect them in his own way.

Izaya Orihara's younger sister and the older twin. Despite her active appearance in a gym suit and bloomers, she carries a quiet, dark atmosphere. She has a unique way of speaking, using single kanji characters with specific readings. Though she seems timid, she is ruthless toward hostility. Believing that she and her sister Mairu can become "one complete person," they have aligned their personalities and tastes to be symmetrical. She handles crises using tools like pepper spray. Her chat handle is "Kyo."

Izaya Orihara's younger sister and the younger twin. She looks like a literary girl with glasses, a single braid, and a black sailor uniform, but her personality is bright and high-energy. She has high physical ability from going to the gym and can take down opponents if there isn't a massive size difference. Aiming for the ideal of "two people as one" with her sister Kururi, she has crafted her personality and specialties to be symmetrical. She shows no mercy to those who cause harm. Her chat handle is "Mai."

A first-year student in Class 1-A at Raira Academy. He appears to be a quiet, ordinary boy, but he has a strong longing for the "extraordinary" and possesses the initiative and ability to handle crises when they arise. He is close to his childhood friend Masaomi Kida and harbors secret feelings for Anri Sonohara. Online, he serves as a gentle moderator under the name "Tanaka Taro," and by extension, became one of the founders of the Dollars. As the organization grows, he becomes its practical central figure.

A tall young man working as a debt collector in Ikebukuro. Usually mild-mannered and hating violence, he was born with the limiters on his emotions and muscle strength broken; despite being a normal human, he boasts top-tier monstrous strength and durability. He fears his own power and wishes for peace, but he is at loggerheads with Izaya Orihara and will chase him around throwing vending machines whenever they meet. He likes sweets and milk.

A mad scientist living in Ikebukuro as an underground doctor. He dotes on the Headless Rider, Celty, and speaks in a unique style frequently using four-character idioms. He is a former classmate of Shizuo, Izaya, and Kadota. In the beginning, they are at odds over Celty's "face," but he eventually confesses his love, they become lovers, and their relationship deepens. In the end, he risked his life to stop Celty from leaving.

The "Headless Rider" urban legend of Ikebukuro, a Dullahan wearing a cat-eared helmet and a jet-black suit. She came to Ikebukuro searching for her lost head. While she manipulates a scythe and a motorcycle (her companion Shooter) made of shadows, her personality is sensible, caring, and "gallant." After Shinra's confession, she became his lover, and even when faced with the chance to regain her head, she ultimately chooses to stay in Ikebukuro with Shinra.