Sundahl (Shuichi Ikeda) once says "Let's just see the performance of your Earth ninjutsu!", a nod to one of Char Aznable's famous quotes.note "Let's just see what the Federation's mobile suit is capable of!"
In Ten Years After, Ikkou's musical group apparently includes Yusuke Tomoi; they tell the audience he's apparently home with the measles and certainly not off fighting monsters as a green superhero — which he did ten years before as Kamen Rider Gills.
Also in Ten Years After, Nanami's idol career was reaching its sell-by date, so to speak, and her manager was asking her to consider doing a Hotter and Sexier production. Which Nao Nagasawa already did, in Koichi Sakamoto's DTV movie Dimension Travellers.
No Export for You: Neither this, nor its western counterpart Power Rangers Ninja Storm, were dubbed in Korea. The common speculation is that both series were skipped because depictions of ninjas are culturally taboo in Korea. In reality, when the decision was made to dub Super Sentai in Korea over Power Rangers (as they have been doing since Mighty Morphin' Power Rangers), they skipped to Bakuryuu Sentai Abaranger since Super Sentai is at least a year ahead of Power Rangers. Ninjas are not as taboo in Korea as Samurais are, which is why Naruto airs there without any problem.
Then again, when it came time to find a replacement for the very taboo Samurai Sentai Shinkenger, Hurricaneger was skipped again in favor of the one before it, Gaoranger.