Ayahi Takagaki is a Japanese actress, voice actress, and singer born in Tokyo on October 25, 1985. She is affiliated with the talent agency Music Ray'n and is also a member of the voice actor unit Sphere. A graduate of Musashino Music University, she majored in operatic singing, a background that strongly informs her performance style.

Takagaki's career began after she successfully passed the Music Ray'n Super Voice Actor Audition while still a university student in 2006. Her professional debut came shortly thereafter with a role in the anime Ouran High School Host Club. She secured her first leading role in the 2007 series Venus Versus Virus. Her early career featured a range of significant parts, including Jasmine in Deltora Quest, Feldt Grace in Mobile Suit Gundam 00, and Noe Isurugi in True Tears.

Takagaki is known for her wide vocal range, capable of portraying characters from young children to mature women, including gentle, serious, and boyish roles. Some of her most notable and long-running roles include Chris Yukine in the Symphogear series, Lisbeth (Rika Shinozaki) in the Sword Art Online franchise, Mikako Satsukitane in Heaven's Lost Property, and Erika Karisawa in Durarara!!. Her filmography also includes Derieri in The Seven Deadly Sins, Henrietta in Log Horizon, Wakana Sakai in Tari Tari, and Tadakuni's sister in Daily Lives of High School Boys.

In 2009, Takagaki formed the musical group Sphere with fellow Music Ray'n voice actresses Haruka Tomatsu, Aki Toyosaki, and Minako Kotobuki. The group has released multiple singles and albums and performed theme songs for various anime. Her formal training in opera is evident in her singing, which is frequently showcased in character songs and her solo career. She made her solo debut in 2010 with the single Kimi ga Iru Basho. Her solo discography includes several singles and albums, many of which have been used as theme songs for anime series in which she also starred, such as Symphogear. Her cover mini-album series, melodia, features her interpretations of well-known songs, including classical pieces and musical standards.