Complex sentence: The anime series was never released in the United States, likely due to the perceived lack of interest of the subject matter; in fact, even in Japan, it is one of the few sports anime to have dealt with rhythmic gymnastics.
Split into simpler sentences: The anime series was never released in the United States, likely due to the perceived lack of interest of the subject matter. In fact, even in Japan, it is one of the few sports anime to have dealt with rhythmic gymnastics.