A good bit of episode 1 of Durarara!!×2 Ten (i.e. episode 13 of the broader "second season") was narrated by one of the female characters. But this show has a gorillion characters, and I can't place which one of them it was.
The end credits list the following female characters for this episode:
Sonohara Anri (Hanazawa Kana) Celty (Sawashiro Miyuki)
- Karisawa Erika (Takagaki Ayahi)
- Yagiri Namie (Kobayashi Sanae)
Awakusu Akane (Kuno Misaki)
- Mamiya Manami (Tanoue Marina)
- Kamichika Rio (Tomatsu Haruka)
- "Nurse" (Yamamura Hibiku)
- "Woman" (Satou Kanami)
I've struck through the ones where I'm familiar enough with the voice actor to know it can't be them.