Ren Elise Jewelria grew up alongside Lala and happens to be the female version of Run Elise Jewelria—they're the same person, basically. Both are royalty from the planet Memorze, where their kind can shift between male and female forms at will. For Ren and Run, the trigger is surprisingly mundane: a sneeze.
The split personality thing creates some classic romantic tension. Ren's got feelings for Lala, while Run is interested in Rito instead. This naturally makes things messy—Ren can't stand Rito because he's the one Lala's into, and Run resents Lala for the same reason, since Rito happens to like her. So depending on which version shows up, you're dealing with completely different dynamics and priorities.
Content compiled by AnimeList.moe from publicly available sources.
