Set in the year AD 2225, mankind has spread from Earth to inhabit nearly all the planets or nearby moons in colonies and settlements. space travel has grown and improved to the point of being commonplace. For the inhabitants of the solar system, an astronaut career isn't out of the question, and one of the schools set up to train future space voyagers is the Liebe Delta, a space station positioned somewhere in Earth's orbit. This growth is despite the mysterious phenomenon known as the Geduld, a sea of plasma that suddenly erupted from the sun along the Earth's orbital plane in AD 2137. Stretching from the sun to the edge of the solar system, this area of high temperatures and gravity pressures has never been explained.

The part that I want to emphasize in this anime is that it is very realistic and character development is absolutely amazing. It is not the scientific side that is realistic. (I assume from the appearance of non-existent scientific terms that the producer didn't even intend to make it realistic) You see the people psychologically breaking down, which the phenomenon, according to NASA, would happen if there is not enough number of people whom you don't recognize are in a closed space. The estimated required number of people in a community for it to sustain for a year is 1000 people, which is not reached in Ryvius's case. What must be noted is the slow development of the story that actually contributes to the character development.