Fourth Tokyo, one of JapanA's new prefectures on Mars. Kirishina City, Fourth TokyoA's special economic zone, is home to an elite corporation, renowned for its aerospace business - the Kirishina Corporation. The company runs a private school, the Kirishina Science and Technology Academy High School. There, the students report to the company after school to take part in a crucial project, the development of prototype variants for rockets. This is the Kirishina CorporationA's Advanced Technological Development Department, Educational Development Class, a.k.a. A-TEC. When a new student set to join the class is kidnapped en route to Mars, the A-TEC students embark on an unprecedented rescue mission.