idol
In the Japanese context, idols are generally young entertainers with a combination of singing and dancing, who usually wear very showy or frilly outfits.
Several game, manga and anime series include idols or are even centered around idols, including Idolmaster, Love Live!, Aikatsu!, the Pretty series, Uta no Prince-sama, Macross, and Mahou no Tenshi Creamy Mami, the latter two being generally considered the start of idols in anime.
Fans dedicated to a single idol are participating in oshi-katsu.
Not to be confused with a certain star-shaped planet.