I sought out this CD and scanned the cover art because, to my knowledge, it features one of the most complete set of protagonists from the Toei Magical Girl Series (東映魔女っ子シリーズ).
The album's title is Great Magical Girl Strategy Special Song Collection (魔女っ子大作戦 スペシャル·ソング·コレクション). As with so many of these crossover images from the Toei series, it's associated with the Great Magical Girl Strategy (魔女っ子 大作戦) video game from 1999 (平成11).
The only possible missing piece here would be Magical Girl Tickle (魔女っ子チックル) . I would expect her to be present more often when Toei promotes the series if she were meant to be included. But, she is included as part of a different CD -- The Dream of a Singing Girl ~Toei Animation Magical Girl Anime Complete Works~ (歌いつがれる少女の夢 ~東映動画魔法少女アニメ全集~).
