I must admit, I'm not the biggest One Piece fan there is. I've read the first four volumes of the manga, read some of the Alabasta story arc in Shonen Jump, and watched the movie based on a slimmed down version of the Alabasta story arc. It's a great series, wildly imaginative - I'd recommend anyone who's interested to check it out. Yet it's not a series I've continued to keep reading, or watching, regularly. I suppose the main reason for that is the always heightened state of emotions all the characters possess; all the time. Passion and exuberance are great to see in characters, but it used so often it gets diluted to the point where I can't take this excited energy for long. (And the series is loooooong, even surpassing Dragon Ball's 42 volumes with a whopping 62 volumes!) The series is good, and I enjoyed what I've read of it. But it's not for me long term.
What might interest people is that Kaizoku Sentai Gokaiger has a lot of similar themes inspired from One Piece. This is nothing new -- Super Sentai series often take what's popular and makes a series based around the concept; Magiranger clearly was going along with the Harry Potter craze that swept the world.
I thought I'd point out some of the similarities the two series have. Mind you, this is probably all the obvious stuff fans of both series already know about; this list is for anyone who doesn't know about the connection between the two series.
The Strawhat Pirates / Gokaiger
Obviously, One Piece and Gokaiger both feature pirates. They similarly have special boats they rely on, which act as their home and HQ -- but most importantly both groups are good hearted. Monkey D. Luffy and crew regularly help people in need. Luffy has the dream of finding the ultimate treasure, the "One Piece", so he can become the Pirate King. Similarly Captain Marvelous has the goal of discovering the Greatest Treasure in the Universe. Both are vague goals, but help motivate the characters down the path of piracy. Another thing both groups both enjoy is notoriety -- especially from the law. The Strawhat Pirates are wanted by the Navy, under the command of the World Government, while the Gokaigers are wanted by the corrupt Space Empire Zangyack.
Luffy / GokaiRed
Captain Marvelous isn't exactly the same as Luffy, though. Luffy is laid back, a bit dumb at times, but always fights for his friends and his dreams. Captain Marvelous similarly fights for what's right, but is much more reserved in being obvious about it. He's also proved rather competent, leading the Gokaigers in a successful rebellion against the Zangyack. There are two notable similarities between the characters.'
Both of them like meat. Luffy and Marvelous seem to have a similarly voracious appetite.
And, more importantly, they both have fabled and beloved mentors who they are trying to emulate. Luffy was inspired to become a pirate by Shanks, leader of the Red-Haired Pirates. Marvelous was mentored by AkaRed.
Zolo / GokaiBlue
Zolo and Joe have a few things in common as well. They both began as enemies to pirates. Zolo use to be a Bounty Hunter, who hunted pirates, and Joe use to be a solider in the Zangyack Empire. What is most notable about the two is -
- both of them being expert swordsmen, even excelling in multiple sword carrying techniques.
Nami / GokaiYellow
Nami and Luka Millfy share a similar gun-ho attitude to treasure hunting, always aiming for treasure at ever opportunity. Nami use to be pick-pocket before joining up with Luffy and the Strawhat Pirates, and Luka use to live in poverty before she began rebelling against the Zangyack Empire.
Usopp / GokaiGreen
Usopp and Don Dogoier are both the resident worriers of the group. They both have skills with technical equipment and keep things working for the crew. They can both be brave, when the moment is right, but it takes some doing for them to build up the confidence to act.
Vivi / GokaiPink
Vivi might not have been a permanent member of the Strawhat Pirates, but I think she might have been a loose inspiration for Ahim de Famille. They are both Princesses; Vivi relied on the help of Luffy and the Strawhat Pirates to help save her country of Alabasta, while Ahim lost her kingdom and people when they where destroyed by the Zangyack. Vivi wanted to stay with Luffy and crew, but her responsibilities to Alabasta outweighed the adventure of being a pirate. Ahim seemed more thrust into the role of a pirate, finding haven among Marvelous' crew.
I'm sure there are a bunch of other nods to One Piece weaved into the Gokaiger series, but the ones I listed above are the most obvious ones to me. If you know more about One Piece than I do, free to leave comments if you want to add any other similarities you know about.