Sae Otsuka is a Japanese voice actor and singer-songwriter born on October 10, 1995, in Kanagawa Prefecture. She is affiliated with no talent agency, working as a freelancer. Otsuka made her voice acting debut in 2015 with her casting as Hanae Tae in the multimedia franchise BanG Dream!, a role that became a defining part of her early career. Her interest in music began in early childhood, and she started composing songs at the age of five. Before entering the voice acting industry, she gained experience performing as a street musician, an activity she began in 2011. Learning to play the electric guitar for her BanG Dream! audition was a pivotal moment that connected her performance skills directly to her voice acting work.

Otsuka is primarily known for her roles in projects centered on music and performance. In addition to Hanae Tae in the BanG Dream! anime, films, and game BanG Dream! Girls Band Party!, her major anime and game roles include Maria Ibu in Future Card Buddyfight, Laura in Bermuda Triangle: Colorful Pastorale, and Sotoorihime in the game Megami Meguri. She also voiced Nagisa Tsukiyama in the D4DJ multimedia project. In the 2024 series Togane! Chronicle, she plays the character Meguru Tokisaka. Her work is frequently tied to ensemble casts in long-running, multi-platform franchises, leading to recurring collaborations with other voice actors and production teams involved in these projects.

Beyond voice acting, Otsuka has pursued a parallel career as a solo singer-songwriter. She made her solo debut in 2020 with the mini-album Avantitle under the avex trax label. As a solo artist, she writes and composes her own music, performing as a guitarist and vocalist. Her musical style and skills are closely intertwined with her voice acting roles, particularly in music-themed franchises.