Complex sentence: Many new characters are introduced in the course of the film, and it is strongly recommended to watch its sequel, the three-part OVA series Legend of Crystania: the Chaos Ring, which goes into the story in further detail.
Split into simpler sentences: Many new characters are introduced in the course of the film. Its sequel, the three-part OVA series Legend of Crystania: the Chaos Ring, goes into the story in further detail.