There were official novels such as "Mech Suit Gundam: The Iron Blood's Orphan Girl","Mech Suit Gundam: A Moment of Grief","Mech Suit Gundam UA","Mech Suit Gundam TWILIGH Axis", and "Mech Suit Gundam The Origin". Among them,"The Original" was a remade manga, but it was also a novel created according to the official settings. However, the recommended "My Mecha Battle Simulation Machine Has Come True" and "The Descent of the Gundam King" were both derivative doujinshi novels. I hope you like this fairy's recommendation. Muah ~😗