Minami, already well-established as a voice actress, was in the indie band Re-X and met Shiina through a friend.
In 2005, Minami and Shiina were joined by Joe Rinoie as an additional singer and composer, changing the group's name to II MIX⊿DELTA for a limited time.
In 2008, Shiina started his solo music project ShiinaTactix-Music, featuring different female vocalists, Sanae Kobayashi, Yoko Hikasa and Mutsumi Tamura.
In 2013, Two-Mix released a digital download single "T-R-Y: Next / Across The End: Platinum Stream" and Shiina composed the music for a song "Rhythm Linkage" with Yoko Hikasa in her album "Hikasa Yoko Collaboration Album Glamorous Songs".
In 2014, Shiina composed the music for a song "Reboot Tactics" with Kaori Sadohara (from Sweet Arms) in their album "Trigger".