2006, Shikoku's shipping city faces the Seto Inland Sea. Akio Hoshigami, a girl who lost her dream of becoming a track and field athlete due to a leg injury, entered high school with her best friend Ayano Umisoe. Club activities and meeting new friends, Meizakura, who was empty, is gradually regaining her former self. However, one day Saiki suddenly disappears. On this planet, there have been battles that have continued since ancient times. Once given to God, eight giants with empty souls "Star Machina".
