- Nicknames: Acchan
- Birthday: September 27, 1990
- Age: 28
- Joined: August 2015
- Previous names: Kuramoto Aoi / 倉本あおい
- Lyrics Written: Primitive, Pearl, Shakai no Rule
- Member Colour: Purple
- “Glasses” member
She went to a performing arts school and began to dream of being an idol.
She started participating in various auditions, despite her parents not being supportive of her decision to pursue a career in showbiz. Because of this she faked consent letters, pretending to be her parents, to be able to go to auditions when she was underage.
Once she graduated high school, she left her parents a note, took 30,000 yen (£200) and went back to Tokyo to pursue her dreams of becoming an idol.
She worked in Haneda Airport and lived in the staff dorm to save up money.
After going to various auditions, she joined different idol groups, but all eventually disbanded after members left.
One of these groups was Fleur in 2013 – 2014, which she performed under the name 倉本あおい / Kuramoto Aoi. She didn’t wear glasses during her time in the group.
She applied for BiSH during their initial auditions, but didn’t get through. Second time around, after changing her appearance and adopting her signature glasses, she made it.
They revealed in an interview that each member has a part of their wages go in to fund Atsuko’s glasses. She has several pairs, some more expensive than others. She has said many times that if she takes off her glasses, she’ll be fired.
On December 22, 2018 it was announced, by Watanabe during a live performance, that Atsuko will be the next BiSH member to have her own solo debut. This will likely be released sometime in 2019.