On August 21, 2015, Sugai along with 22 other members were announced for the newly created idol group, Toriizaka46, renamed shortly after into Keyakizaka46 and again into Sakurazaka46 in 2020.
[3] Her nicknames include Yukka (ゆっかー) and Sugai-sama (菅井様), the latter referring to her "wealthy young lady" (お嬢様, ojō-sama) persona.
As part of the subunit, Sugai made center appearances in three songs: "Aozora Chigau" in "Sekai ni wa Ai Shika Nai", "Wareta Sumaho" in "Fukyōwaon, and "Namiuchigiwa o Hashiranai ka?"
[14] On August 22, 2022, Sugai announced that she will be leaving Sakurazaka46 after the Tokyo Dome performances on November 8 and 9, the final leg of the national tour that will begin in September that year.
[21] On June 7, 2017, Sugai was appointed the Special Ambassador for the Japan Equestrian Federation [ja], in order to broaden the appeal of the sport.
[24] Her first post-Sakurazaka46 activity was an acting role in the stage play Neo Bakumatsu Junjoden, which ran from January 28 to February 19, 2023.
[31] On November 29, 2023, her 28th birthday, Sugai announced via Instagram her transfer to the talent agency Top Coat.