In the mysterious future, crystalline organisms called Gems inhabit a world that has been destroyed by six meteors. Each Gem is assigned a role in order to fight against the Lunarians, a species who attacks them in order to shatter their bodies and use them as decorations. Phosphophyllite, also known as Phos, is a young and fragile Gem who dreams of helping their friends in the war effort. Instead, they are told to compile an encyclopedia because of their delicate condition. After begrudgingly embarking on this task, Phos meets Cinnabar, an intelligent gem who has been relegated to patrolling the isolated island at night because of the corrosive poison their body creates. After seeing how unhappy Cinnabar is, Phos decides to find a role that both of the rejected Gems can enjoy. Houseki no Kuni follows Phos' efforts to be useful and protect their fellow Gems. [Written by MAL Rewrite]

"Period" is how magic users called who beat "Spiral"—monsters that were summoned from isolation. Due to the rise of these beings, 14-year-old apprentice Period Haru, who is a part of the Eighth Arc-end Division, is called to break the cycle and cast himself into the endless battle. However, a mysterious thievery occurred and sank the division into bankruptcy, forcing Haru and his other comrades have to leave their headquarters. To rebuild a branch, they have to overcome quest after quest. (Source: MAL News)

Ginga Eiyuu Densetsu Gaiden (1999) is the second of two OVA adaptations of side stories from the Ginga Eiyuu Densetsu novel series. This second adaptation follows the achievements of Yang Wen-li of the Free Planets Alliance before the fateful Battle of Astarte, and continues the tales of Reinhard von Müsel and Siegfried Kircheis of the Galactic Empire. Spiral Labyrinth Yang is propelled to the spotlight after his famous evacuation of civilians from El Facil. Following an unofficial double promotion and a flurry of media attention, he chronicles his research of the Year 730 Mafia—a close-knit group of Alliance military officers centered around the famed tactician Bruce Ashbey. He investigates a startling claim by Ashbey's deceased widow that may have enormous political ramifications: that the great war hero was not killed in action but murdered. The Mutineer Reinhard and Kircheis are posted on the destroyer Hameln II, docked at Iserlohn Fortress. After gaining the respect of the crew, Reinhard's leadership is tested when the captain is severely wounded and passes command authority to Reinhard, the next-highest ranking officer on deck. The Duelist While Reinhard and Kircheis are working in the Imperial capital Odin, Reinhard learns of a mining rights dispute involving Dorothea von Schaffhausen, a friend of his sister Annerose von Grünewald. Upon hearing that Count Herxheimer intends to settle the matter with a duel, Reinhard volunteers to represent the Schaffhausen family. The Retriever After falling out of favor with the nobility, Count Herxheimer is trying to escape to the Free Planets Alliance with a stolen Seffle particle generator prototype. Reinhard is tasked with retrieving both the prototype and the defector, but is only assigned the cruiser Hässliche Entlein due to the confidential nature of the mission. The Third Battle of Tiamat To commemorate the 30th year of the reign of Kaiser Friedrich IV, the Empire announces a large-scale military campaign against the Free Planets Alliance. In the ensuing clash between the Imperial expeditionary force and three Alliance fleets, Reinhard's timely intervention shapes the tides of war. The Neighbor Concluding the OVA series and spanning episodes 29 to 31, Reinhard and Kircheis discover that while Count Herxheimer may be a member of the nobility, he is not just a normal neighbor from next door. They hatch a meticulous plan with the Galactic Empire’s best sniper to take the neighbor down. [Written by MAL Rewrite]

Ginga Eiyuu Densetsu Gaiden is the first of two OVA adaptations of side stories from the Ginga Eiyuu Densetsu novel series. This first adaptation follows the achievements of Reinhard von Müsel and Siegfried Kircheis of the Galactic Empire before the fateful Battle of Astarte. The Silver-White Valley Reinhard and Kircheis graduate from their military academy and are immediately sent to the frozen frontier planet Kapche-Lanka. Unbeknownst to them, their new superior schemes to kill Reinhard on behalf of a rival of Reinhard's sister Annerose von Grünewald. Dreams of the Morning, Songs of the Night Reinhard and Kircheis are assigned to the Imperial Military Police, where they uncover the corrupt and oppressive practices of the Empire's law enforcement. They are soon ordered to investigate the murder of a student at their alma mater. Dishonor As Reinhard awaits the bestowal of his new title of Count von Lohengramm, he sends Kircheis to the artificial resort satellite Kreuznach III for a vacation. Restless from the lack of work, Kircheis assists the local police with a drug trafficking case related to an attack on a disgraced former Vice Admiral. A Hundred Billion Stars, a Hundred Billion Lights While Reinhard is still a commodore in charge of only a single squadron, he laments the incompetence of his superiors during a battle against the Free Planets Alliance. Amassing military successes under the direct command of Vice Admiral Richard von Grimmelshausen, Reinhard repeatedly clashes with Hermann von Lüneburg, a commodore and former regimental commander of the Alliance's infamous Rosen Ritter. [Written by MAL Rewrite]