The film is a documentary that follows the lives of a group of teenagers, primarily focusing on two young men named Romio (played by himself) and Jun (played by himself), who are part of the "Bosozoku" motorcycle gang culture in Japan.
Instead of actors, "Romio no aoi Sora" features the real individuals involved in the story. So, the people you see on screen are not actors playing characters but rather real teenagers living their lives.