Erika Nakai is a Japanese voice actress and singer who began her career using that name before changing it to Ayuru Ōhashi in April 2009. Born in Tokyo on April 28, 1984, she has been active in the entertainment industry since 2005 and is affiliated with the agency Mausu Promotion, having previously been associated with the ToriTori agency until June 2015.

Her most iconic role is that of Eila Ilmatar Juutilainen in the Strike Witches franchise, a character she has voiced across multiple television series, including the original 2008 season, Strike Witches 2, the 2012 film, and the 2019 series Strike Witches 501st Unit, Taking Off. She has also reprised the character in the related series Brave Witches. Beyond Strike Witches, her notable anime roles include Aoi in the original net animation and television adaptation of Wish Upon the Pleiades, Adele Barrufet in Horizon in the Middle of Nowhere, Oryō in Girls und Panzer, Anju Yuuki in the Love Live! School Idol Project, and Tomoki Sawamura in Saki. Her film work includes reprising her role as Oryō in various Girls und Panzer movies and as Momo Aoki in High School Fleet: The Movie.

In addition to her voice acting, she has also been involved in music related to her anime roles, performing character songs for series such as Strike Witches. Her career also includes work in video games, with roles such as Emily Rankin in Sudeki: Sennen no Akatsuki no Monogatari and as her character Oryō in the game Girls und Panzer: Senshadō, Kiwamemasu.