- Birthday: August 20, 1999
- Age: 20
- Height: 163cm
- Joined: December 18, 2019 (MAMESHiBA NO TAiGUN founding member)
- Member colour: Blue
Previously worked in a hospital.
Nao was a member of an iDOL STREET trainee group, Sapporo Snow♡Loveits from April 2, 2013 until her graduation on September 14, 2016.
She took part in the 2019 WACK audition under the name Bashiyasume Atsuko / バシヤスメ・アツコ. On the first day, she ranked 11th/22 in the singing evaluation. She was kicked out on day 5 after failing to perform the most squats to BiS’s song ‘Paprika’. [x]
She took part in the collaboration TV show between WACK and Wednesday’s Downtown, for Kuro-chan’s segment ‘MONSTER IDOL’. She passed the audition process and went on to be a founding member of the group, MAMESHiBA NO TAiGUN / 豆柴の大群.
• Sapporo Snow♡Loveits / サッポロSnow♡Loveits – Trainee Idol Group – April 2, 2013 – September 14, 2016 (as Yokoyama Nao / 横山奈央)
• MONSTER IDOL – TV Audition – November 6, 2019 – December 18, 2019 (as NAO / ナオ)
• MAMESHiBA NO TAiGUN / 豆柴の大群 – Idol Group – December 18, 2019 – present day (founding member) (as NAO OF NAO / ナオ・オブ・ナオ)