Nanako Matsushima is a prominent Japanese actress who has also performed voice roles in anime productions. She is primarily known for her extensive career in live-action film and television, where she has established herself as one of Japan's leading actresses through roles in the horror film Ring and numerous television dramas. Her forays into voice acting, while limited, have been in high-profile animated features.

Matsushima's first experience with voice acting came in the 2009 television anime special Jungle Emperor Leo, where she voiced the character Eliza. This project, produced to commemorate the 50th anniversary of Fuji Television, marked her debut in the field. She later commented on the unique challenge of voice acting, noting that conveying emotion using only her voice was difficult and required multiple recording attempts to meet the director's satisfaction.

Her most notable voice acting role came in 2014 when she joined the cast of Studio Ghibli's animated film When Marnie Was There, directed by Hiromasa Yonebayashi. In this, her first feature-length voice acting role, she portrayed Yoriko Sasaki, the kind foster mother of the protagonist, Anna. This casting was significant as it marked her first involvement with a Studio Ghibli production, and she was among several high-profile Japanese actors brought on to voice the film's characters. Matsushima's performance contributed to the film, which was critically acclaimed and received a nomination for Best Animated Feature at the 88th Academy Awards.

While a recurring collaboration with a specific anime director or studio beyond these two projects is not evident from her voice acting credits, her role in When Marnie Was There represents a notable instance of a major live-action actress contributing to a prestigious animated feature. Her achievements in voice acting are therefore tied to her participation in these significant works, bringing her established acting skills to the world of animation.