In the year 179 of the New Western Calendar, the One Year War breaks out between the Earth Federation and the Principality of Zeon, but is halted when an object crashes to Earth, landing on South Atalia Island.
In the year 186, the Excelion battleship (from Gunbuster) battle a force of STMCs (Space Terrible Monster Crowd) when they are suddenly attacked by another alien fleet, known as the Aerogaters.. .