Based on the Phantasy Star Online 2 MMORPG published by SEGA. It covers the first three episodes of the original game and an original story. The game storyline follows members of a planetary exploration organization ARKS, based on the colony fleet Oracle that's searching for a habitable planet for its population. The members of ARKS defend Oracle and other planets from monsters called Darkers, which are under the control of the villainous Dark Falzes.
Watch Phantasy Star Online 2: Episode Oracle episode 1 online — subbed and dubbed, with automatic AniList / MyAnimeList progress sync.