Koe de Oshigoto!: The ANIMATION

Being asked to work as a voice actress at a game company might not be so bad, unless you are Kanna Aoyagi. On her 16th birthday, her older sister Yayoi guilts Kanna into doing voice work for her at Blue March, a game company that specializes in eroge: erotic games with lots of sexual content.

Sweet and innocent, Kanna has no idea how she can possibly succeed at such an occupation when she has no sexual experience. But as she plays eroge for research, uses her vivid imagination, and receives unorthodox help from her coworkers, Kanna slowly becomes more comfortable with her new, embarrassing profession.

(Source: MAL Rewrite)