|Okai Asuna, June 2018|
|Legal Name||Yajima Asuna (矢島明日菜)|
|Born||May 14, 1996|
|Agency||UP-FRONT AGENCY (2004-2010)|
|Label||UP-FRONT WORKS (2004-2010)|
|Associated Acts||Hello Pro Egg, Okai Chisato|
|Joined||June 20, 2004|
|Left||November 28, 2010|
|Time in Group||6 Years, 5 Months, 9 Days|
On November 28, Okai withdrew from Hello! Project after the 2010 Hello! Project Shinjin Kouen 11gatsu ~Yokohama JUMP!~.
On June 3, Asuna announced to her Instagram followers that she was 7 months pregnant and due in September. She gave birth to her second child on September 21, later named Toa.
- Name: Okai Asuna (岡井明日菜)
- Nickname: Assuu (あっすー), Asunan (あすなん), Asunyaa (あすにゃあ)
- Birthdate: May 14, 1996
- Birthplace: Tokorozawa, Saitama, Japan
- Bloodtype: A
- Height: 156cm
- Western Zodiac: Taurus
- Eastern Zodiac: Rat
- Hello! Project Groups:
- Hello Pro Egg (2004-2010)
-  Kaba 3 (かば3)
- She eats bread for breakfast.
- Has a habit of referring to herself as "Asuna"
- Her favorite spot is at the top of her two-floored bed.
- She sometimes appears in her sister's blog, but because she's no longer in the agency, her face is usually censored.
- Her husband has the same last name as Yajima Maimi.