- Name: Sainen Mia (西念未彩)
- Nicknames: Sainen (さいねん), Mia (みあ), MIA
- Birthday: June 22, 1993
- Birthplace: Tokyo, Japan
- Blood type: A
- Height: 156 cm
- Favorite food: Shrimp
- Least favorite food: Mabo tofu
- Favorite color: Red, green
- Likes: Collecting knick-knacks, red umbrella, the word "jonetsu"
- Hobby: Listening to music, reading comics
- Specialty: Swimming
- Favorite School Subject: English
- Least favorite school subject: Japanese
- Looks Up To: Takahashi Ai
- Hello! Project groups:
- Hello! Pro Egg (2004–2010)
- Eats Japanese-style for breakfast.
- Has a habit of rubbing her nose.
- Her favorite spot is her perfectly sized room.
- She is close friends with Mutou Mika and Yutoku Ayumi.
- Has a younger brother.
- Was an assistant during the Metro Rabbits H.P. match at Hello! Project SPORTS FESTIVAL 2006.
- [2006.11.01] 江戸から着信!?～タイムスリップto圏外！～ (Edo Kara Chakushin!? ~Time Slip to Kengai!~)
- [2007.11.03] リバース！～私の体どこですか？～ (Reverse! ~Watashi no Karada Doko Desu ka?~)
- [2009.11.04~08] Rin Toshite
- [05.06.2008] Tokito Ami with H!P Egg Ehon Stage – EHON JAPAN 2008