Minako Kotobuki
Takagaki graduated from a music college in Tokyo, with a major in operatic singing. Her first musical performance was the opening theme of the 2009 "First Love Limited" series, titled "Future Stream" with Aki Toyosaki, Haruka Tomatsu, and Minako Kotobuki. Shortly after, the four formed the musical group Sphere. They are affiliated with Music Ray'n, an artist management and publishing group of Sony Music Entertainment Japan. The theme was released as the group's first single on April 22, 2009. In July, the anime series "Sora no Manimani" debuted with the Sphere performed opening theme "Super Noisy Nova", which was released as a single on July 29, 2009. Sphere released their third single "It Raises the Wind/Brave my heart" on November 25, 2009. The group released their first album "Atmosphere" on December 23, 2009. After, the group performed "Realove:Realife", the opening theme of "Ichiban Ushiro no Daimaō", which aired in April 2010.