Glay is a Japanese rock band formed in Hakodate in 1988. The core four members, vocalist Teru, guitarists Takuro and Hisashi, and bassist Jiro, have been together since 1992. Primarily composing songs in the rock and pop genres, they have also arranged songs using elements from a variety of other genres, including progressive rock, punk, gothic rock, electronic, R&B, folk, gospel, reggae, and ska. Originally a visual kei band, the group slowly shifted to less dramatic attire through the years. With five million copies sold, Glay's 1997 compilation album Review is the fifth best-selling album of all time in Japan. Their July 1999 concert "Expo '99" at Makuhari Messe was attended by 200,000 people, making it the largest-ticketed concert ever held by a single act at the time. As of 2008, Glay had sold an estimated 51 million records; 28 million singles and 23 million albums, making them one of the top ten best-selling artists of all time in Japan.

Yoshiki Hayashi , known as Yoshiki, is a Japanese musician, songwriter, composer, record producer, film director, and fashion designer. He is best known as the leader of the visual kei rock bands X Japan and the Last Rockstars, for which he is the drummer, pianist, and main songwriter. He has been described by Billboard as a "musical innovator" and named "one of the most influential composers in Japanese history" by Consequence. Yoshiki's solo career includes several classical studio albums and collaborations with artists such as George Martin, Bono, will.i.am, St. Vincent, the Chainsmokers, Skrillex, Ellie Goulding, Stan Lee, Roger Taylor and Brian May of Queen, Gene Simmons and KISS, Nicole Scherzinger, and Sarah Brightman.