 In 1986, Shiga played the role of Yumi Hanazono, the main character in "Magical Idol Pastel Yumi".Her single, "Freesia no Shōnen", was used as a theme song for the same series, and this helped her gain in popularity.After playing the role of Yumi and performing the theme song for the series, she officially made her debut as an idol singer under Warner Pioneer.