Phantom Siita (ファントムシータ / 怪忌蝶) is an idol girl group produced by Ado. The group made their official debut on June 26, 2024 with the digital single "Otomodachi". There are currently four members: Miu, Rinka, Moka and Mona. Founding member Hisui left May 31, 2025. Read more on Last.fm