The younger brother of the twin unit Twinkle Bell. Satsuki loves pranks and is always going around plotting them. He marches to the beat of his own drum. Although Satsuki is mean on one side, he does a complete 180 when it's about his beloved older brother Mutsuki Kururugi, whom he's a complete brocon for. He listens to Mutsuki's opinions and advice readily. The two of them are together 24/7, proclaiming, "We come as a two-in-one package!." (Source: Etoile Stage Wiki)