Yū Sasahara is a Japanese voice actress from Kumamoto Prefecture, born on April 30. She is affiliated with the talent agency I'm Enterprise and has been active in the industry since 2016. Her path to voice acting was influenced by her early interest in music; she learned piano as a child and played the clarinet in her junior high school brass band. Although she initially dreamed of becoming a singer, her parents were hesitant. Her father later suggested voice acting as a career that would allow her to sing, act, and appear on television, which sparked her interest in the profession. He even printed out an audition form for a film dub to encourage her. This led her to investigate the industry more seriously during high school.

To pursue this new goal, Sasahara enrolled in the Japan Narration Acting Institute during her third year of high school, attending the school while also studying at university. In her third year of training, she was accepted into the I'm Enterprise agency, marking the official start of her professional career in 2016. Her earliest roles included minor characters in series such as Love Live! Sunshine!! and Classicaloid, with her first named role coming in 2018 as Li Xuelan in Märchen Mädchen.

The year 2018 proved to be a significant turning point when she was cast as Akari Amano in the anime television series Ms. Vampire who lives in my neighborhood. This role, a human girl who becomes fascinated with and moves in with a modern, non-violent vampire, marked her first main character and helped establish her presence in the industry.

Following her debut leading role, Sasahara's career continued to build with a variety of parts. In 2019, she was cast as Rū Hitoma in Over Drive Girl 1/6 and as Rin Namiki in the multimedia franchise Kandagawa Jet Girls. The year 2020 saw her take on multiple roles, including Yūki Kuroiwa in the fishing anime Diary of Our Days at the Breakwater, Salsa in the multimedia project Lapis Re:LiGHTs, and Nua Nakamachi in Dropout Idol Fruit Tart. In these productions, she also participated in theme song performances, connecting her work to her early musical aspirations.

A major role came in 2021 when she was cast as the protagonist Emilico in the critically acclaimed anime Shadows House. In this series, she voiced the cheerful and hardworking living doll who serves as the "face" for a mysterious, soot-covered noble child, a performance that required a wide range of emotion and energy. Her filmography from this period also includes a role in Platinum End.

Sasahara's work has continued to expand across both anime and video games. In 2022, she voiced Kurumi Nanba in Fuuto PI and had a role in the popular series Chainsaw Man. She has also become a recognizable voice in the gaming world, with notable roles including the racehorse Curren Chan in Uma Musume Pretty Derby, the USS Boise in Azur Lane, and the character Kirin in both Azure Striker Gunvolt 3 and its sequel. More recently, she has voiced Lynette in the globally popular game Genshin Impact and Verina in Wuthering Waves. Her anime roles in 2023 and 2024 include Yayoi Hozuki in Dark Gathering and the title character Puniru in Puniru is a Cute Slime, for which she also performed the theme song.