Orangestar is the stage name of Aiji Satou (born August 20, 1997), a Japanese Vocaloid producer, songwriter, and composer who has been active since 2013. He began uploading original songs to YouTube and Niconico in 2013, often using synthetic singers such as Hatsune Miku and IA, and became known in online Japanese music for melodic, high-energy digital pop built from electronic production, clear hooks, emotional phrasing, and a light, airy sound. Rather than heavy or abrasive production, his arrangements usually emphasize brightness, momentum, and open space, placing his work at the intersection of internet music culture, contemporary J-pop sensibilities, and the broader Vocaloid scene. Representative songs include 『アスノヨゾラ哨戒班 (feat. IA) 』 and 『DAYBREAK FRONTLINE (feat. IA) 』.
After moving with his family to Utah in 2014, he released his first album 『未完成エイトビーツ』 on April 22, 2015; it later reached No. 45 on Oricon's weekly chart. He followed it with 『SEASIDE SOLILOQUIES』 in 2017, then paused musical activities from 2017 to 2019 while serving as a missionary in Riverside, California, before resuming in 2020 and marrying Kase (夏背) that year. His later work includes 『オーバーシーズ・ハイウェイ』 for ウォルピスカーター, used as an ending theme for 『デジモンアドベンチャー』 in 2020. In 2026 he served as the theme song artist for Agents of the Four Seasons: Dance of Spring; WIT Studio animated the music video for the opening theme song, and "Petals feat. Kase (夏背)" was used as the OP of "Shunkashuutou Daikousha".
