While at Miyamasuzaka,
Shibuya, with a friend, she was scouted by an Incent staff. Deguchi had previously been scouted by several other agencies before [to which she all declined], but admiring actress and model
Mizuki Yamamoto, whom she heard was from the agency, she accepted the offer. She debuted in March 2018. Her first job after joining Incent was a photo shoot for the fast fashion brand "Shimamura". On August 23, it was announced at the 2018 Seventeen Summer School Festival held at
Pacifico Yokohama National Hall that six contestants, including Deguchi, had been selected as "Miss Seventeen 2018". With
Suzu Hirose "graduating" as the exclusive model for the said magazine at the end of the event, the six
Miss Seventeen candidates took part in an interview photo shoot. Deguchi was selected as the " IMAGE GIRL 2019", they made photo collages of various clothing items incorporating loafers that was then later published in
Seventeen and on Haruta's official website. She starred in her first television appearance in the TV drama
Cocoa, which aired in January 2019, it was a drama adaptation of the grand prize winning work of the , with an omnibus format which follows three high school girls played by
Sara Minami, Deguchi, and
Riko Nagase as the main characters. In the second episode of the TV drama
Love Sickness and the Guys in BS
Nippon Television, which began airing in July of the same year, she appeared as the middle school classmate of the main character played by
Ryuga Sato. In April 2021, She appeared regularly in two dramas: ''
in Mainichi Broadcasting and Kotaro Lives Alone'' in
TV Asahi. In December 2020, she made her very first movie appearance as the young Isabella in the movie
The Promised Neverland. On July 22, 2022, with the summer issue of
Seventeen released, after four years, she "graduated" from being their exclusive model. On September 16 of the same year, she made another appearance in the movie
Silent Parade, playing the role of Natsumi Namiki. She then became an exclusive model for women's fashion magazine
Non-no for the December issue which was released on October 20. She co-starred with
Nana Mori in the original drama
The Makanai: Cooking for the Maiko House scheduled to be released on
Netflix on January 13, 2023, Deguchi plays the role of Sumire, marking her first lead role in a drama. Her first photo book entitled
liberte was released on March 24, 2023. In the same year, she was also cast as the lead role of Futaba Yoshioka in the two-season
live action television adaptation of the
shōjo manga Blue Spring Ride. Then, in 2026, she reprised the role of Futaba Yoshioka – a character from her earlier work – in the second season of the television adaptation of the manga
Strobe Edge. == Filmography ==