After meeting a dancing old man in what she thinks is just a crazy dream, a preteen schoolgirl embarks on a series of fanservice-filled magical girl adventures with a little creature named Ongo who might be evil and a shy girl with mysterious powers named Nami. (Source: ANN)

Tokyo is currently experiencing rain showers that seem to disrupt the usual pace of everyone living there to no end. Amidst this seemingly eternal downpour arrives the runaway high school student Hodaka Morishima, who struggles to financially support himself—ending up with a job at a small-time publisher. At the same time, the orphaned Hina Amano also strives to find work to sustain herself and her younger brother. Both fates intertwine when Hodaka attempts to rescue Hina from shady men, deciding to run away together. Subsequently, Hodaka discovers that Hina has a strange yet astounding power: the ability to call out the sun whenever she prays for it. With Tokyo's unusual weather in mind, Hodaka sees the potential of this ability. He suggests that Hina should become a "sunshine girl"—someone who will clear the sky for people when they need it the most. Things begin looking up for them at first. However, it is common knowledge that power always comes with a hefty price... [Written by MAL Rewrite]

In the future (subsequent to the events of the television series) Kate, Rose, Rachel and Claire divide their immortal lives between study and vigilantism. Their past link to the red garden on Roosevelt Island comes back to haunt them after mysterious transfer students Louise and Edgar seek out their friendship.

The ten Sailor Guardians have gathered for the final battle. However, the Queen of the Dead Moon, Nehelenia, attacks with the power of her "nightmares". While Helios uses his last ounce of strength to save the Earth, Usagi is drawn into Nehelenia's nightmare, but is encouraged by the strong heart of Tuxedo Mask. Joining forces with her fellow Super Sailor Guardians, she transforms into Eternal Sailor Moon. Finally, all "Eternalized" Sailor Guardians have gathered.