"Pretty Guardian Sailor Moon Eternal" is a two-part anime film adaptation of the "Dream" arc from Naoko Takeuchi's manga "Sailor Moon." The story continues from the events of "Sailor Moon Crystal" and focuses on the Sailor Guardians as they confront a new threat during a solar eclipse. The narrative begins with Usagi Tsukino, also known as Sailor Moon, and her friends preparing for a rare celestial event. However, the eclipse brings chaos as the Dead Moon Circus, led by the malevolent Queen Nehelenia, emerges to spread nightmares and steal the pure dream mirrors of Earth's inhabitants.

The Sailor Guardians discover that the Dead Moon Circus aims to capture the Golden Crystal, a powerful artifact tied to the legendary Golden Kingdom. This crystal is revealed to be connected to Chibiusa, Usagi's future daughter, who is targeted by the villains due to her unique bond with the artifact. As the Dead Moon Circus sows fear and despair, the Sailor Guardians must awaken their true powers as Eternal Sailor Guardians to combat the threat. The story delves into the lore of the Golden Kingdom and the tragic past of Queen Nehelenia, who was once a ruler consumed by jealousy and darkness.

Key characters include Usagi Tsukino (Sailor Moon), Mamoru Chiba (Tuxedo Mask), Chibiusa (Sailor Chibi Moon), and the Inner and Outer Sailor Guardians: Ami (Sailor Mercury), Rei (Sailor Mars), Makoto (Sailor Jupiter), Minako (Sailor Venus), Haruka (Sailor Uranus), Michiru (Sailor Neptune), Setsuna (Sailor Pluto), and Hotaru (Sailor Saturn). Each character plays a pivotal role in the battle against the Dead Moon Circus, with their relationships and growth further explored. The narrative culminates in a climactic showdown where the Sailor Guardians unite to protect Earth and restore hope, ultimately confronting Queen Nehelenia and her minions, including Zirconia and the Amazoness Quartet.

The film expands on themes of love, friendship, and the enduring power of dreams, while maintaining the core elements of the "Sailor Moon" franchise. It balances action, emotional moments, and character development, providing a cohesive continuation of the series' overarching storyline.