Amped wrote:15.Seishun Night 青春Night (Unreleased new song written by Tsunku, arranged by Okubo Kaoru, Rap arrangement by female rapper Miss Monday, who is the wife of U.M.E.D.Y.), funky song with rap. Fans report they saw a small notation saying it is a new single, but no release date.
Morning Musume. '19 new song "Seishun Night" (concert recording)
https://www.zeta-uploader.com/en/14965745