Durarara!! Episode 12

"My days were always pretty uncomplicated, not too full of hope or despair. And they're still like that. It's just that now, I find them incredibly satisfying. Here I am, and there you are. If you can find redemption in me, then I can do the same for you."

- Celty Sturluson

"Yin and Yang" is the twelfth episode of the Durarara!! anime.

Synopsis
Celty Sturluson protects Mikado Ryuugamine from Seiji Yagiri, who demands 'Celty' back. As she swings her scythe, she is stopped by the redheaded girl, whom Mikado suddently recognizes as Mika Harima. Staring at the face of the crying and screaming Mika, Celty realizes that the head on Mika's shoulders is not hers.

Mika confesses and apologizes for pretending to be the head Seiji loves. Seiji is shocked, but Mikado admires that Seiji and Mika both took a lot of risks for each other and remarks on their similarities. As the Dollars crowd disperses, Izaya Orihara congratulates Mikado on the turnout and offers a warning about the constant desire for evolution.

Realizing who the doctor who operated on Mika must be, Celty confronts and prepares to question Shinra Kishitani, but Shinra asks and answers all of her questions and reaffirms his love for her. He reveals his fear of losing Celty if she were to find her head, since it is Celty's lack of a head that allows her to remain in Japan and act so much like a human. When Celty shares her fear of dying due to the vulnerability of her missing head, Shinra finds it amusing they are both getting worked up over hypothetical situations.

The next day, everything returns to normal. At Raira Academy, Masaomi Kida explains to Mikado an outsider's view of the previous night's events. Seiji and Mika reconcile and agree to move forward together, and Mikado thinks about Izaya's words.

In his apartment in Shinjuku, Izaya meets with Namie Yagiri. He suspects that Celty's head is sleeping, waiting to awaken during a war, and reveals his plans to start a war that only he can win using all the factions in Ikebukuro at his disposal.

Chatroom

The day after the Dollars meeting, TarouTanaka states that he did not get enough sleep the previous night and wonders to Setton if Kanra will come on. Setton has to go almost immediately, however, and the chatroom is left empty.

Character Appearances
In order of appearance, excluding the opening song:

Cultural References

 * The company Nebula that is mentioned to be buying out Yagiri Pharmaceuticals is the same company in Baccano! that manages immortal-related incidents. Both Baccano! and Durarara!! are works in the Naritaverse.

Quotes

 * Izaya (to Seiji): "Well, you couldn't even tell the difference between the genuine article and the fake. Guess your love wasn't that strong after all. Sucks to be you."
 * Celty (to Shinra): "I'm scared, too. I'm scared of dying."
 * Izaya: "Human beings defy imagination."
 * Izaya (to Mikado): "Remember: I know you came here to Tokyo hoping to escape the hum-drum, but in about six months this will all seem pretty ordinary to you. At that rate, you'll have to move to another country to keep things exciting. Or start looking for things that are a little more 'underground.' But, I'd be willing to bet that you would get bored of that in just a few days as well. The only way to truly escape the mundane is for you to constantly be evolving. Whether you choose to aim high or aim low, enjoy each day for what it is."
 * Izaya: "Hey Namie, why don't we all go to Heaven?"