Fast review 'bout the RAW of the movie!
There's so many spoilers here, but if you've watched Den-O and Decade all the way through, none of this should come as a surprise to you.
Soooo, today I watched Chou Den-O And Decade: Onigashima Battleship--or rather, as it should be called, "Chou Den-O and Chou Zeronos--Oh, And Decade Is Here Too. So Is Trollie, But Blink And You'll Miss Him, Probably Because He Went Off To Go Get Sexed Up By Yuusuke He Is A Troll."
So the main character of CD-O + Decade...
...is a young boy from Tokyo, who apparently lost his mother in some unexplained accident and is now living in the countryside. He's really squeamish--bugs and mud freak him out--and he's bullied constantly. So, what's this kid's name?
Yuu-chan.
Yes, it's that Yuu-chan.
So apparently Team Den-O has gone to Yuuto's past in order to stop a pair of oni brothers from summoning a massive time-traveling battleship. This was brought up briefly at the end of the Den-O arc in Decade, so now you get to see what Team Den-O was doing while Tsukasa smirked his way into the next world. : D
Kotaro (and by Kotaro I mean kid-Ryoutaro) is Den-O once more. He's a bit older now as well.
It's kind of interesting to see this version of Ryoutaro being so un-accident prone/unlucky/scared--but then again, this version of Ryoutaro has probably been fighting imagin for a while now.
Koutarou (And by Koutarou I mean Ryoutaro's grandson from the future) is also fighting with Team Den-O as Chou Den-O. Confusing, no?
After hanging out with Team Den-O and the little kid version of his grandfather for so long, Koutarou is no longer a jerk. He calls Kotaro "jii-chan" and is more then happy to spend time with everyone on the Denliner.
So basically, young Yuu-chan is being targeted by these two oni brothers (and their army of gelnewts...who apparently decided to go looking for work after Ryuki) who want a magatama that he has. Kid-Ryoutarou tells Yuu-chan that he's come to help him, and that if he gets into trouble, he can get on the Denliner with them.
: D I can tell that they're going to be good friends.
So, stuff happens, Yuu-chan ends up getting on the Denliner, and they swing on down to 20's Japan to pick up a few friends.
For some inexplicable, unexplainable reason, the Taros (minus Momo) are possessing the armament dudes from Kiva, who are in the past with them. What?
Then again, this is a pure fanservice kinda film, so why the hell not?
At least Duckface wasn't in attendance. Also, Matsuda Kenji as Kintaros? : D Yeeeeesplz.
Team Den-O makes another pit stop to pick up Sieg....
...who's found a very suitable host. Tsukasa is the best Sieg, hands fucking down.
Then they hurtle back into the past again, run into some archer chick named Toki, and then shit happens.
This also happens as well. KIDDY DENEB AND KINTAROS? ER.
I won't talk about the battles and whatnot because they're so fucking sweet and I don't want to spoil them, but I will say this:
HI TROLLIE.
LAKSGJDKLSJGKDLSJGKLSDJKLDJLDS G3 HOLY FUUUUUUUUUUUUUCK! HIKAWA! BB! \O/
Onore Dikeido Tsukasa then shows up to deal with Trollie's trolling, and Deneb does THE AWESOMEST SHIT EEEVAAAR~
And then Onore-kun goes and gets possessed for the majority of the main battle. Lulz. Also HOLY FUCK, CHOU VEGA FORM IS FUCKING SEXY.
Anyway, without giving away much more of the movie, I'll leave you all with this:
"It's a promise, right, Deneb?"
"It's a promise, Yuuto!"