As promised here's a long thread of all of Kuuga's concept art and my opinions on them

Kind of interesting since some of this stuff just simply carries on to Agito while there are other concepts that can go as far as into Ex-aid

Here we got the first designs of Kuuga's first name-Kamen Rider U7

It's kind of got these RiderMan vibes but it was supposed to be some sort of moon samurai rider

But they didn't stray too far from Showa considering he has a triple Typhoon driver
(for reference Ichigo had a single typhoon while V3 had a double typhoon)

So it seems like Kuuga(U7) might have initially be planned to be a sort of spiritual successor to Ichigo and V3

Next we got these cool monstrous looking Kuuga concept arts which got this Amazon and Shin vibe to it this time around
I love how the first one's scarf looks like insect wings

Also apparently Kuuga wasn't always planned to be a solo rider
This was planned to be a female rider in Kuuga called 'Kamen Rider Lady'(Very creative)

So Kuuga almost had the first female rider before Ryuki took that spot

Kamen Rider Leon here was another planned rider in Kuuga that they got rid of for whatever reason

Guess they didn't want him to have a furry sidekick lol
Tho I quite like this design(kind of looks like if Kraven from spiderman was a friendly kamen rider)

Here we got Kuuga's version of Zi-O's "what's my helmet gonna be?" shot

They def were struggling to get away from that Showa aesthetic since we see that one that's basically just Black RX and Amazon

This looks like an evolution of that Amazon looking design from before
Also if you notice, he still has the triple typhoon

I like the other one better tho since this one just looks like the old one but less monstrous

Idk what the hell they were thinking when they got that creepy alien Kuuga

The trippy circles are an interesting concept if it wasn't for the fleshy colors

I quite like his torso having a face tho

But the whole alien + Mexican royalty thing just doesn't work lol

This had to be like some sort of planned villain rider(maybe the last one was too) since they can't have wanted the main rider to look like Darth Vader fused with Shadow Moon

Machine Skullman would have been a cool villain tho if Kuuga was tech focused

The one on the right had to be my favorite evolution of the amazon inspired Kuuga concept art

First of all the triple typhoon being stacked on top of each other look great

Also they seem to also have a monster form like Amazon but with two giant typhoons on each side

I'm thinking at one point they might have actually planned to have Kuuga be some fusion of all Showa Riders

That design literally has features of most main showa riderss and the triple typhoon I mentioned earlier

Kind of like Kuuga is the literal successor of all of them

The moon samurai Kuuga also got a new concept

I like the cute little cat fangs it has and how it's a lot more metallic

(it might have something to do with that villain rider from earlier and Kamen Rider Leon)

Here we got yet another cat rider

I'm thinking they decided 3 riders in Kuuga was too much and they said fuck it and fused Kamen Rider Lady and Kamen Rider Leon together into one rider called Yoroi Rider

Right here looks like they just went back to the drawing board and decided to make Kuuga a grasshopper rider without realizing they just made Kuuga a yellow Black RX

That big bulging grasshopper face is creepy tho lol

Right here looks like they were experimenting with some more tech based Kuuga's
Still looks like the subtly carried over the Amazon inspiration

They obviously continued with this tech Kuuga design so much that they basically made him an Ultraman lol

After this it seems they wanted the Heisei Rider look to be basically just Showa but with tech

Especially with all these alien and metallic looking Showa-esque designs

They also decided Kuuga Ultraman wasn't enough so they made Kuuga Bumblebee

Now it's starting to look like the Kuuga we know and love

Seems to me they still got that tech Showa thing still going on tho

This seems to be a continuation of that design

Guessing the more horns Kuuga had, the stronger the form

So I'm guessing the first was growing, pink is mighty, and gold is Amazing or Ultimate

Right here they basically had Kuuga already & if you look closely, you'll see that they clearly didn't want to go through this long & tedious process of finding a perfect design so they just made one of his old concepts into Agito

You'll see later they recycle many more concepts

Next example of series recycling old Kuuga concepts is that apparently looks like they were planning to give Kuuga his own useless mech thing that we only see for to episodes

Luckily we won't see those till years later

Next part of this long thread is Kuuga's forms

First you'll see that they decided they wanted Kuuga's forms to be animal based(and that Kamen Rider Leon is now a Kuuga form)
His base form would be an Eagle
Other forms seem to be a Tiger & Whale

Also guessing that OOO's might have also took a page from Kuuga's old notes considering his first forms are
Taka
and
Tora
(no Batta but all riders are Batta lol)

Next is the next route they chose to go with forms which is by far my favorite

Instead of changing into animals Kuuga now changes into various insects with different movesets which are
Gun, Sword, Ninja, Dragon(which is just a staff), & base form is just punching things I guess

Seems to still go off of the Tech Showa Kuuga

Also I thought the dragon form might have been an actual dragon but I guess it's just a dragon fly

Here's a variation of the last forms

Something interesting is that this sort of carried over to Kuuga now and Double

Kuuga since we got the Titan Sword

Double since we got the Gun and Staff forms(aka trigger and metal)

Yet another variation of this

I love how the black is the base color and the helmets are cool

This also seems to combine all the previous aspects of the Kuuga concepts and added cool new ones
-Blue seems to be this tech samurai based on the moon samurai design

-Orange has an amazing scorpion staff thing that I wish came back in some way
-The oversized sword still stuck around
-Ninja seemed to be replaced with a crossbow form too(still retaining the tech elements)

Now for my least favorite iteration of Kuuga's concept forms

The large goofy forms with the big weapons look not the best lol

The weird thing is that the rising forms just change the colors of the base forms

For some reason tho I love how amazing mighty looks like and how they just gave Kuuga some oversized lizard to hold

The weirder thing is that this form is seperate for some reason so I'm guess it's supposed to be Amazing

I wonder if the crossbow was actually supposed to be that big tho

This upgrade that has two designs is really cool since it seems that they planned to give Kuuga a form where he separates in two which seems to later become Mighty Brothers XX all the way back in Kuuga

The forms themselves look great too and they all use previous weapons

The other option is given if you look at this scan

It seems that Kuuga's base forms would be seperate while his upgrade forms would combine two of his base forms
at a time which allows him to use two different weapons

(you can tell cuz of the use of coloring in all of them)

Only reason I said it could have split Kuuga into two is that if you look carefully it has a form for each combination of forms(it's kind of like if Double had a CyloneJoker and a JokerCyclone form)

Problem is that they'd have to make 20 different suits just for this powerup

Also think it's interesting to note that these two are basically just parts of Ryuki's helmet

The cool gold form with the majestic wings is probably just this concept's form of Amazing or Ultimate

Some more examples of the whole Gun, Sword, Crossbow(or whatever he's holding) forms

These Kuuga forms just look like a sentai but you can see now they wanted more of a through line but only this time they made the green form the base instead of red

(also it seems they tried mixing in elements with these forms given that red looks all firey)

These ones obviously look a lot closer to home
-The wings on red are always welcome
-It seems that at some point they wanted a yellow kuuga form that's this weird magi staff based form idk

Love how the initial rising forms just decide to add more abs lol

Starting to look like the final result apart from the weapons

Growing looks like it originally was gonna be pink or red

Here's the last of the base forms where we see a more watered down growing, this take on the forms where they add some magic circle things around parts of the design and the planned idea of just adding more abs to the rising forms lol

Here's the first serious attempt at the rising upgrades

Instead of adding more abs everywhere they now are adding more gold everywhere for the rising forms

I still would have preferred the form mixing that we saw earlier in the concepts

This seems to be an old attempt at a late Kuuga form
Just looks like stronger but I'm really liking how they were considering giving Kuuga these wing cape things

This initial design for Kuuga Ultimate seems ridiculous but I love it

First of all it's solid gold . . .

Second of all his little arm weapon is literally powered by a second arm mounted driver . . .

Just pure rawness

Here is where they decided that making that design solid gold was rediculous so they mixed in black and silver

I'm happy they kept the arm mounted driver tho

Here is more of them testing what mixtures of gold silver and black look the best for Ultimate Kuuga

This one here with the wing cape, the arm sword and the silver has got to be my favorite

Like I love Kuuga Ultimate but I'm kind of mad that this wasn't Kuuga Ultimate lol

Here is when they just decided to make Kuuga Ultimate into Agito Ultimate before Agito even existed

This is the point where they decided that Ultimate Kuuga having an arm mounted driver weapon was not cool for whatever reason

The chest markings are cool tho

This is just the most beta looking Kuuga ultimate lol

The chest markings on the first Kuuga Ultimate look quite cool.
Second one is cool too but the bulky chest piece throws me off a little

They went a little wild with these Kuuga Ultimates but I honestly don't mind

The oversized capes and chest markings are dope

I quiet like this one

I wish this would have at least became Rising Ultimate lol

Here's a more minimalistic approach

It looks good but it's kind of meh when you compare it too all the solid gold kuugas with arm swords, capes, and chest markings from before lol

Here's some sketches that are a continuation of the last

The large wings and red veins are pretty cool tho

It's slowly starting to look like the ultimate we all know and love

The smaller spikes are a nice touch that I wish they kept

AND DONE!!!
Wow Kuuga has come so far

I don't know if all rider's have a concept stage as long and convoluted as Kuuga but it was pretty cool looking through all this stuff

By far my favorite discoveries

1-Kuuga could have at one point been some spiritual successor of Showa Riders
2-Kuuga's line of forms could have been super diverse(including a form swap gimmick for rising)
3-Ultimate originally having an arm mounted driver that powered a weapon

These are also my favorite Kuuga concept designs

The driver sword

The triple stacked typhoon

The super diverse base forms

They're all too cool