ラブライブ三昧 is a special music program of NHK FM 今日は一日○○三昧, which plays music of a theme (e.g., from one singer, of one genre, or from a multimedia project like Love Live!) for the entire afternoon and evening.
The program today (May 4, 2022) includes songs from each group of the Love Live! project, that is μ’s, Aqours, Nijigasaki High School Idol Club (虹ヶ咲学園スクールアイドル同好会), and Liella!, and also some songs by individual members.
Love Live! is an influential project with fans from all over the world. Many fans, even though not necessarily listening to the program, are posting under the hashtag to join the party.
Check out NHK FM’s program 今日は一日○○三昧. If you are interested you can learn more on wikipeida about Love Live!.