Fake Nationality: Steven Skyler, Antonio's actor, is not Spanish at all. He's Thai/German and just happens to look kinda Spanish. [It's especially funny because Hector David, Jr. (Mike the Green Ranger), really is Latino, though not actually Spanish (different sources claim he's either Puerto Rican or Cuban.)]
Additionally, despite being about Samurai and being the most Japan-centric season Rangers has ever done, Erika Fong (the Asian member of the team) is actually descended from a Korean mother and Chinese father. Eventually you have to wonder if maybe the ancient Samurai deliberately did this to protect their families and throw off the Nighlocks.
Many assumed that Deker was meant to be Japanese, giving how close the series was sticking to Shinkenger. However, this seems to have been averted, as his backstory has been altered.
May not have been averted. See Where The Hell Is Springfield? on the main page, plus there's the fact that Dayu refers to him as her brave samurai when they exchange wedding gifts, so either those two are Japanese or Samurai takes place in a world where samurai settled all over the world.
Mean Character, Nice Actor: According to the reports that came out of Power Morphicon, Rick Medina (Deker) was very down to earth and friendly. It's especially interesting, because he had the exact opposite problem after Wild Force. After playing good guy Cole, he then appeared on the reality show Kept, where he had a reputation as an egotistical Jackass. Either he's mellowed in recent years, or he was Genre Savvy enough to realize that the really annoying people on reality shows usually get the most airtime, and was working it to his advantage.
One of Us: With the exception of Steven Skyler (who said he didn't watch much TV at all as a kid,) all the Ranger actors have mentioned watching Power Rangers as kids and being fans when they were younger. Take that with a grain of salt, since a few sounded like they were being told what to say (and odds are pretty good at least one of them wouldn't have been)... with the exception of Hector David, Jr. (Mike), who's clearly getting the biggest thrill out of it.
Screwed by the Network: Besides being underpromoted, as well as having to comply with Nickelodeon's "20 episodes per season" limit (resulting in the show having to produce a "second season"), the most recent hiatus during the Super Samurai season lasted for five months, during which time Nickelodeon Latin America already broadcast the final episodes.note As a result, they can't be advertised as "world premiere" episodes. There has been speculation that Nickelodeon may have been deliberately trying to get the show cancelled.
According to a recent interview, during the audition process, at one point, they moved Hector David, Jr. over to the Gold Ranger.
Originally Amit Bhaumik proposed that this series was to take place in Stone Canyon and Mia would be a relative of Cassie but Jonathan Tzachor decided not to go with this idea.
As it turns out, there's quite a lot of ideas Bhaumik had that were rejected, as this Tumblr post reveals. A few details that stand out:
The Red Samurai Ranger was going to be a Japanese-American young man named Mark Ozawa, descendent of a long line of samurai who fought against the Ashura Clan. His main rival would be a young man named Keiji Ayakawa, who would be revealed early on to be a descendent of Master Xandred, who in this version was defeated and petrified as a statue. Xandred would return, however, serving as the show's Bigger Bad. Keiji, jealous of Mark's samurai legacy, would readily join the Ashura Clan, as well as have the ability to transform into a demon (this would be Juzo's counterpart).
The other four Rangers would hail from different countries, such as Austria, Nigeria, the UK, and Mexico.
Bulk would have a larger role, running a sushi restaurant the Rangers would hang out in. Along with his nephew, Eugene (a prototype for Spike), they would help the Rangers, similar to the kuroko.
Eugene would eventually become the Gold Ranger, creating his own morpher behind the others' backs.
The Ashura Clan operated from the Dread Castle, a demonic version of the Osaka Castle in Japan. The Moogers were originally called "Marauders," and Akumaro/Serrator would originally be a mystic who betrayed the Red Ranger's family, resurrected by Octoroo (here named "Octomancer") as a demon.
Mark would hand over the title of Red Ranger to his cousin Alison (Kaoru's counterpart) when it is discovered that he is actually a descendent of the Ashura Clan.
Really, there's a lot of information. Check out the link above for a massive case of What Could Have Been.