Yokoyama Nao became a 4th generation member of street-sei, a trainee unit under the iDOL STREET label, and its subgroup, SAPPORO Snow♥Loveits on April 1st, 2013. She graduated from SAPPORO Snow♥Loveits. and street-sei on September 14th, 2016.
In 2019, Nao participated in the WACK AUDiTiON CAMP under the name Bashiyasume Atsuko. She was eliminated from the audition on the fifth day for failing to perform enough situps. Afterward, she auditioned for WACK again, with her progress being broadcast as MONSTER IDOL.
On December 18th, during the final episode of MONSTER IDOL, Nao was announced as one of the show's winners and debuted in MAMESHiBA NO TAiGUN. Her debut single, Restart, was released the following day.
Nao expanded her stage name to "Nao Of Nao" on January 1st, 2020, and a few days later, was announced as a mentor for the upcoming WACK AUDiTiON CAMP 2020.
On February 18th, photos of Nao drinking alcohol were published in the tabloid magazine, "FLASH", which claimed that they had been taken before she had reached the Japanese legal drinking age of 20. An announcement was later made on MAMESHiBA NO TAiGUN's website, confirming the report and apologizing for any trouble this may have caused. The report also stated that, while Nao has already reached the age of adulthood, she will be urged to reflect on the seriousness of her actions and closely supervised to prevent any further incidents. Nao herself also apologized on twitter.
Worked in a hospital before taking part in MONSTER IDOL.
- [2019.11.11] IDOL -Aa, Mujou-
- [2019.11.06] MONSTER IDOL
- Was a member of SAPPORO Snow♥Loveits at the same time as Kaede.
- Her audition name was a parody of Hashiyasume Atsuko.
- She was able to do 31 sit-ups for her redemption challenge, ranking the last out of all participants that were eliminated that day.
- Her hobby is listening to music.
- Has been learning to dance since she was 3 years old.
- Hates losing.
- Her favourite idol is BiSH.