Written by. Nick Mosier based on the original Japanese article (original article’s publication date: 2022-01-07 08:51 JST) Sakanaction vocalist Ichiro Yamaguchi suddenly surprised fans with a tweet saying, “Umapyoi! Umapyoi!” “Umapyoi” being thought to refer to the theme song of Uma Musume Pretty Derby, “Umapyoi Densetsu.” In September of last year, Yamaguchi praised the song on a radio program,