- Name: Kitahara Sayaka (北原沙弥香)
- Nickname: Saaya (さぁや)
- Birthday: November 29, 1993
- Birthplace: Saitama, Japan
- Blood Type: A
- Height: 163 cm
- Favorite food: Sweets, fruit
- Least favorite food: Pork, spicy food
- Favorite color: Strong pink
- Likes: Rhinestones
- Dislikes: English, maths, fat on meat
- Hobby: Cooking, singing, collecting hand towels
- Specialty: Tennis, Japanese
- Looks Up To: Yoshizawa Hitomi
- Hello! Project groups:
Kitahara Sayaka joined Hello! Project in 2004 as a member of Hello! Pro Egg along with 32 other girls. As an Egg Sayaka spent years learning to dance, sing and act. She was a back-up dancer for Hello! Project concerts throughout the years.
In 2008 Sayaka was placed into the group MilkyWay along with fellow egg Kikkawa Yuu and Morning Musume member Kusumi Koharu. This group sang the theme song and other songs within the anime Kirarin Revolution in which Sayaka also provided voice acting for one of the main characters. While in MilkyWay Sayaka took part in two singles and four compilation albums for the anime. Once the anime ended the group became defunct and Sayaka would only then take part in egg activities.
On April 21, 2011 it was revealed that Sayaka would debut as a soloist under the FRAME section of Up Front Group under the name Sorano Aoi (CV: Kitahara Sayaka). The single titled Yappa Seishun will be the ending song for the anime Inuzama Eleven GO in which Sayaka provides the voice work for the character Sorano Aoi. The single will be released under the Piccolo Town label.
In July 2013 Sayaka became part of a duo which featured her pairing up with a new seiyuu from the Inazuma Eleven GO Galaxy series each single, and every single being used as a theme song to both the animated series and various video game releases.
In 2019, Sayaka joined the voice cast of The IDOLM@STER: Shiny Colors as the character Izumi Mei and joined the unit, Straylight.
- [2013.03.06] Haru no Gradation (春のグラデーション) (Sorano Aoi (CV: Kitahara Sayaka))
- [2011.06.22] Yappa Seishun (やっぱ青春) (Sorano Aoi (CV: Kitahara Sayaka))
- [2011.11.09] Kanari Junjou (かなり純情) (Sorano Aoi (CV: Kitahara Sayaka))
- [2012.02.08] HAJIKE-YO!! (Sorano Aoi (CV: Kitahara Sayaka))
- [2012.06.13] Natsu ga Yattekuru (夏がやってくる) (Sorano Aoi (CV: Kitahara Sayaka))
Compilations / Other
-  Kaidan Shin Mimibukuro Kaiki (怪談新耳袋 怪奇)
- - Kirarin Revolution (きらりん☆レボリューション) (as Yukino Noel)
- [2011.05.04-] Inazuma Eleven GO (イナズマイレブンGO) (as Sorano Aoi)
- [2007.09.22] Hello! Pro Egg Delivery Station! 01 (ハロプロエッグデリバリーステーション！01) (with Kikkawa Yuu, Mori Saki, Ogawa Saki, Aoki Erina)
- [2006.11.01] Edo Kara Chakushin!? ~Time Slip to Kengai!~ (江戸から着信!?～タイムスリップto圏外！～)
- [2009.11.04~08] Rin Toshite
- [2010.04.08~11] Kaibutsu no Kodomo
- Eat's rice for breakfast.
- Has a habit of biting her lip.
- Her favorite spot is the bed at her house.
- She has a hamster, Hamuchan, and two cats, Nyantan and Kokochan.
- As of November 23, 2007 she was noted as the tallest member of Hello! Pro Egg. (She is no longer the tallest.)
- Took part in the second idol wrestling event produced by Tsunku, "Dai 2 Kai "Shinken Onna no Jin The☆ Killer Contents!", on 12/29/2010.