Planck Stars

Planck Stars (プランクスターズ), stylized as PLANCK STARS, is a Japanese idol girl group, originally from Hiroshima, but relocated to Tokyo in October 2025. They made their debut in 2018 and reached mainstream success in 2021. As of September 24, 2026 [refresh], they are on hiatus due to problematic behavior; a successor group named Prankclean Stars has taken their place. Their music is a mix of Rock and electronic dance music. The concept behind them is described as "free-spirited delinquents." The name sounds like "pranksters", which describes many controversies in which the group has been involved. Their antics have ranged from a member exiting the stage mid-song to buy a churro (and not returning until the very end of the concert), to releasing 300 live crickets in the audience. Members have also hammered the ceiling of a venue; slept on stage; stepped on a fan; thrown ink and soy sauce at the audience; spit watermelon seeds into a fan's mouth; and made a fan drink detergent. The concept was born from a desire to go against Japanese idol girl groups culture, who tend to face a lot of boundaries on who they can be and how they must act in public. Members perform wearing extravagant clothing, sing foulmouthed lyrics, and even had a monkey and a dog as official members.