3776 is an idol group in Japan. But now, 3776 is not a group; it is Chiyono Ide’s solo unit. 3776 is read as "Mi-na-na-ro."
Do you know Mt. Fuji in Japan? The elevation of Mt. Fuji is 3776 meters. 3776 is an idol group themed on Mt. Fuji.
Please see this article. Here is a recent interview: https://bassdoom.home.blog/2021/07/25/interview-3776-akira-ishida-and-chiyono-ide/
Several songs are now available in English on streaming services. ("Spring Has Come", "Radio Name") There will be more in the future.
Download (trial listening available): https://ototoy.jp/_/default/p/654722
Download (trial listening available): http://ototoy.jp/_/default/p/56670