Mairu and Kururi Orihara

Mairu and Kururi Orihara are supporting protagonists in the light novel and anime series Durarara!. They are the younger twin sisters of Izaya Orihara, and students at Raira Academy, the same school that Mikado Ryūgamine, Anri Sonohara and Masaomi Kida attend. They are also best friends with Shizuo Heiwajima and big fans of his younger brother, Kasuka.

Mairu is voiced by Eri Kitamura in the Japanese version of the anime and Gina K. Bowes in the English version, while Kururi is voiced by Hisako Kanemoto in the Japanese version and Bridget Hoffman in the English version.

Appearance
Being identical twins, Mairu and Kururi look mostly the same, though there are several ways to tell them apart.

Mairu has brown eyes and long brown hair often tied back in a braid. Her school attire consists of a black sailor uniform with a long skirt, which contrasts with the Raira Academy uniform and, combined with her glasses, gives her the look of a stereotypical bookworm, contrasting with her outgoing nature. Her street attire generally consists of a yellow hoodie with dog ears and a green skirt. Kururi usually wears a similar outfit with an opposite colour scheme.

Kururi has brown eyes, short brown hair, and a well developed bust. She has been shown to wear a variety of outfits over the course of the series, usually wearing an opposite color scheme to her sister. She is first shown wearing a green hoodie with cat ears and yellow skirt while Mairu wears a yellow hoodie with dog ears and a green skirt. Her most common attire is a standard gym uniform with her name written on the front, which earns her attention at school.

Personality
Mairu and Kururi have almost complete opposite personalities; this is due to the fact that, when they were young, no-one was able to tell them apart from each other, not even their older brother Izaya, who asked them what was the point of living when everything they do is the same. To solve this issue, the two rolled dice to decide which of them would get which trait, in order to distinguish themselves from each other, and these have been their personalities ever since. Despite this, they still don't view themselves as separate beings, and are almost always seen together.

Mairu is extremely energetic and outgoing and is a textbook chatterbox in real life. She can also be rather vulgar and usually has no problem going into extreme detail about subjects about sex and pornography even when others are listening, which usually prompts Kururi to calm her down. While usually acting playful in most situations, Mairu has been shown to get serious if there is genuine danger, especially if it might pose a threat to Kururi.

Kururi is softspoken and reserved, rarely reacting to anything with more than a short sentence. She appears to be the more sensible of the twins, frequently reminding Mairu to calm down whenever she gets excited or mischievous. However, Mairu has commented that Kururi can be extremely aggressive at times, though she tends to show it in more subtle means. A prime example is how they each dealt with being bullied. When Mairu was bullied, she confronted her tormentors directly, threatening and physically assaulting them. When Kururi was targeted, she rigged the schoolbag of one of her bullies to light on fire later in the day.

When online, however, Mairu's and Kururi's personalities are swapped around. Mairu usually only replies with short phrases or a single word much like Kururi does in real life. However, her vulgarity still shines through, and she occasionally gets blocked for obscene content. Kururi, on the other hand, is something of a motor mouth, going into long, dramatic tangents and frequently exceeding her word limit in the chat room.