Gaki Race is a Japanese adult video title rather than a mainstream anime series. The name is usually used as a standalone work title, and there is no widely recognized separate franchise or master series title beyond this form. If you are looking for the original title used in Japanese listings, it is typically written in katakana as ガキレース and romanized as Gaki Race. Because it does not appear to have a clearly documented release year in common references, the year is set to -1.