Rena Matsui is a Japanese actress, singer, and voice actor born on July 27, 1991, in Hyogo Prefecture, Japan, though she was raised in Aichi Prefecture. Before establishing herself as a voice actor, she was a prominent member of the Japanese idol group SKE48, joining as a first-generation trainee in 2008, and later also兼任 with Nogizaka46. Her deep connection to anime and manga culture was evident during her idol years, as she was a founder and the fourth president of the SKE48 secondary club, a group for members interested in anime, manga, and games. She also co-hosted the anime information program "Takanori Nishikawa x Rena Matsui ANIMAGA" starting in 2014.

Matsui made her official debut as a voice actor in 2015, providing the voice for the character Junon Kaganemoto in the television anime series "Denpa Kyoshi" (also known as "Electromagnetic Teacher"). This transition from a celebrated idol to a voice actor was a significant step in her career following her graduation from SKE48 later that same year. While her voice acting filmography is selective, she is recognized for her role as Mire Yoshizuki in the 2020 anime film "Looking for Magical DoReMi" (Majo Minarai wo Sagashite). This film is a coming-of-age story celebrating the 20th anniversary of the Ojamajo Doremi series.

Beyond these prominent roles, Matsui's engagement with voice acting also includes narration work, such as for the 2021 film "Inside Zokki". Her career is characterized by a seamless integration of her passions, moving from performing as an idol to voicing characters in the animated world she has long loved. Her work remains focused on her acting and voice acting pursuits under the A-plus agency.