The stage background of "TURN A", in the eyes of today's readers, is similar to the era of the Industrial Revolution in the 19th century. Under this level of technology, it is simply impossible to create MS. However, in the history of this world, it turns out that there is a "Historical Records" called "Black History" (historical stories that record the historical facts of space wars in the old century), and the existence of MOBILESUIT is also confirmed in the "Historical Records". In fact, the fact is that after all the centuries of the universe and its many wars, the earth has been exhausted. All modern civilizations have been destroyed by the war. A small number of people with status abandoned the earth and fled to the moon to live and develop their ancestors. The remaining technology, but most people still remain on the earth, but because the degree of destruction is too severe, the background will be similar to the era of the Industrial Revolution in the 19th century. But these facts are only known to a very small number of "lunar" people, and not at all to people on earth. Most people worship the "WHITEDOLL Stone Statue" (the stone statue that contains the TURNA Gundam) and worship it like a god.

In the plan of returning to the earth advocated by the Queen of the Moon, the people of the moon began to infiltrate into the people of the earth. Extremely advanced mobile weapons were also put into use in the return war. The people on earth simply cannot resist it with extremely backward weapons. With the invasion of MOONRACE and the emergence of TURNA Gundam, people realized that this so-called "legend" turned out to be a true fact, and the future plot is believed to be very closely related to the "black history".

The protagonist Rona (Lan/Na) is an ordinary son of the moon (a resident of the moon). In order to implement the return of Moon Queen Diana to Earth, she was sent to Earth with two other companions. He was almost in danger because he could not adapt to the new environment. He was rescued by the sisters Ji El/Sofia and worked for their family. By chance, he discovered the Turn A Gundam buried in the mine and relied on the experience/judgment of the Children of the Moon to pilot it against the invading Return of the Moon Army. The anime did not specifically label Rona as a New Type. Some details in the play, such as Rona's cross-dressing beauty "Laolun", using Gundam to transport cattle, washing clothes, etc., all add an unprecedented sense of relaxation to this Gundam.

Roland shoulders the expectations of the residents of the moon. He is one of the teenagers sent to prove with his own body that the residents of the moon are suitable for the earth's environment. This is the first step in the fight of the residents of the moon to return to the earth. It can be said to be an act of sacrifice. Roland successfully completed the task. Since the teenagers landed on the earth, they have adapted to the earth's environment and integrated into the earth. They believe that when friends from the moon visit the earth, both the residents of the moon and the people on the earth can hold hands and become friends.

But reality ruthlessly shattered the teenagers’ ideals. The paths of the people of the earth and the inhabitants of the moon are different. If the two small streams are to merge into one big river, perhaps conflict will be inevitable. Roland, who boarded the mobile suit, became the strongest fighting force on earth despite being a lunar man. How will he choose his own destiny in the face of the most admired Queen of the Moon and a group of earth friends who have high hopes for him? What should he do in the face of the love of Queen Sophia and Queen Diana (and even Young Master Gao An)? How will he cope with Turn X, his ultimate rival Jin Karam?