Tametomo Imizu was originally a professional eSports player until he was sought out by the Yellow Kiramai Stone, which detected a sparkle in him, to become KiramaiYellow and defend the Earth from the Yodonheim, who had just destroyed Crystalia and sought to do the same to Earth.
Tametomo met up with the three other professionals who had been recruited by the Kiramai Stones for their sparkles at CARAT, where they received their equipment from CARAT's CEO Muryou Hakataminami and formed the Kiramagers to combat the Yodonheim when they arrived. Until the Red Kiramai Stone chose a wielder to become KiramaiRed, Tametomo served as acting leader of the team.
When the Red Kiramai Stone finally chose a candidate in Juru Atsuta, a seemingly ordinary high school student with immense imagination and artistic skills, Tametomo was skeptical of his ability to serve as leader of the team. However, Juru soon proved himself by using his imagination to conjure the Kiramai Stones into Mashins for the Kiramagers to pilot, and by earning the respect of Sena Hayami and Shigeru Oshikiri by appealing to their passions. Despite this, Tametomo continued to question if Juru was ready to become a leader.