Koji Kikkawa is a Japanese singer-songwriter and actor. He formed the band Complex alongside Tomoyasu Hotei. He released the albums Heroic Rendezvous and MODERN TIME. His songs include Monica, Jealousy Wo Hohoemi Ni Kaete and Setsunasa Wo Korosenai 2014. Kikkawa has also appeared in the film Sword of Desperation and the series Trillion Game. He released the album Over the Nine in 2022.