Yū Asagi is a Japanese voice actor known primarily for work in anime produced under the ComicFesta label, a brand that specializes in releasing two versions of its series: a standard broadcast version and a "complete" or "premium" version with more explicit content. Asagi typically provides the voice for characters in these premium versions, using a stage name separate from the actor credited for the same role in the broadcast edition.

The earliest notable role for Yū Asagi was in the 2018 anime series Shūdengo, Capsule Hotel de, Jōshi ni Binetsu Tsutawaru Yoru, known in English as A Hot Night With My Boss in a Capsule Hotel. In this production, Asagi voiced the male lead, Akihiko Hadano, in the complete version of the series, while Taku Yashiro voiced the character in the broadcast version.

Another significant role came in the 2021 series Yubisaki kara Honki no Netsujō 2: Koibito wa Shōbōshi, the second season of Fire in His Fingertips, known in English as Fire in His Fingertips 2 -My Boyfriend is a Fireman-. In this production, Yū Asagi voiced the character Jun Hase in the premium version of the anime, while Wataru Komada voiced the same character in the on-air version.

This pattern of providing voices for premium versions of adult-oriented anime represents a recurring theme in Yū Asagi's career. This work includes consistent collaboration with the production company ComicFesta and its associated studios, such as Suiseisha and Studio Hōkiboshi, which specialize in this genre of short-form anime.

While the actors who work on standard broadcast versions are publicly listed, voice actors who work under pseudonyms for premium versions, like Yū Asagi, typically have limited public-facing career information available. Their notable achievements are therefore defined by their consistent presence in the specific niche of mature anime productions.