The Ultra Series (ウルトラシリーズ Urutora Shirīzu) is the collective name for all the shows produced by Tsuburaya Productions featuring Ultraman, his many brethren, and the myriad Ultra Monsters. The Ultra Series is one of the prominent tokusatsu superhero genre productions from Japan, along with Toei produced series Kamen Rider, Super Sentai, and the Metal Heroes.
The Kamen Rider and Ultra Series have yet to crossover in a production as big as the former's recent crossover with fellow Toei franchise Super Sentai in Super Hero Taisen. However, they have hed several minor crossovers like as in stage shows. The 1993 TV special, Ultraman vs. Kamen Rider, served to give a comparison between the two franchises and even included a crossover between the first Kamen Rider and the original Ultraman.