Takehito Koyasu, born May 5, 1967, is a Japanese artist whose music career has operated alongside his better-known performance work. As a musician, Koyasu has pursued several distinct projects. In the 1990s, he was a member of the band Weiss Kreuz, which included fellow artists Tomokazu Seki, Shinichiro Miki, and Hiro Yuki. The band served as the inspiration for an anime series of the same name, in which Koyasu also performed as a voice actor. Between 2000 and 2001, he worked within the visual kei scene under the name ZAZEL, releasing a series of works including The Tale of KAY, En La Luna, STELLA, DxD, and Tsubasa. He also maintained a solo career as Koyasu Takehito, active from 1992 to 2007, with a discography that includes Water, Ai no Message (Kokuhaku), MARY & A KITTEN, Piece of T, White Kiss, and ALTERNATIVE.

Yuka Imai, born September 19, 1970, has a music career extensively documented through her work as a performer and vocalist on numerous anime-related albums. Her recorded output includes credits as a vocalist on soundtracks and character song collections for series such as Wedding Peach, Saber Marionette J, Golden Boy, and Kimagure Orange Road. She also has a credit as a composer.

The most significant documented collaboration between Koyasu and Imai as music artists is their work on the original video animation Master of Mosquiton, also known as Master of Mosquiton. For this series, they jointly performed the ending theme song for episodes one through five. The song is titled Invincible Love, known in Japanese as Muteki no Love (無敵のＬＯＶＥ). The single for Muteki no LOVE by Takehito Koyasu and Yuka Imai was released on August 31, 1996, with the catalog number CODC-1004. The song features lyrics by Mizue and Hide, with composition by Hidemi Yamamoto and arrangement by Nobuhiro Makino and Yasuhiro Shigemura. Both Koyasu and Imai are credited for the theme song performance on the Master of Mosquiton Original Soundtrack Vol.1, released on January 21, 1997.