Hey, It's That Guy!: Quite a few Tokusatsu actors crop up in this competition, including Kane Kosugi (Ninja Black/Jiraiya), Mitsuomi Takahashi (Bouken Red/Satoru Akashi), Toshiki Kashu (Agito/Shoichi Tsugami), Kenjiro Ishimaru (Owner), Keisuke Kato (Ixa/Keisuke Nago) and Masahiro Inoue (Decade/Tsukasa Kadoya). G4 doesn't tend to show their runs, apparently because Sasuke draws attention to their Toku roles and copyright issues are involved. However, you can occasionally see them in the audience (in one tournament, Kato and Inoue are sitting next to each other and remarking on other contestants) and they did once show Takahashi run the First Stage, complete with the announcer repeatedly calling him "Bouken Red" (which was subbed).
Kane Kosugi's runs actually are shown, mostly because he was a regular in early seasons (along with his brother Shane) and is better known for action movies than Kakuranger. Likewise Ishimaru, who is one of the oldest competitors to clear the First Stage, and is credited for his travel show and work as a narrator more than being on Den-O.