A giant robot you can sit in and pilot has been unveiled in Japan.

The four-ton prototype - KURATAS - looks like something out of the hugely popular 'Transformers' movies.

It looks as menacing as the Japanese manga super robots but, for now, this machine is just a giant plaything.

What's different about this toy robot is, firstly, its gigantic size, and secondly that it can be operated from within. Its torso doubles as a cockpit where a human pilot can sit and, with the help of motion sensor technology, enjoy the ride.

The robot is the brainchild of artist Kogoro Kurata, and developed in tandem with robotics engineer Wataru Yoshizaki.

It took Kurata more than two-and-a-half years to turn his childhood dream of operating a giant robot into reality.

"I had this vision of the future for robots, which is my passion. But the robots that we're seeing now are all very small, like the Asimo (Honda's android). It seemed unlikely that anyone would develop giant robots however long I wait, and so I thought, I might as well make one myself - that's how it started,” he said.

Funding for the robot's development came out of Kurata's own pockets.

The four-legged robot's steel body stands four meters at its tallest, runs on diesel and can move at a maximum speed of 10 kilometres per hour.

The device is operated from inside the cockpit using either a touchscreen interface coupled with a controller, or a wearable glove which controls the robot's arms and fingers.

The robot can also be controlled remotely - though less comprehensively - using an iPhone or Android-based mobile devices.

The machine runs on an original operating system called "V-Sido" (pronounced bushido), which allows human movement to be translated into robot movement.

The system was created by Yoshizaki, a robotics engineering doctorate student at the Nara Institute for Science and Technology.

He explains that one of the challenges he found was to simplify the complexity of human movement in a way that robots, which have less limbs and dexterity, can imitate.

"There are already many examples of robotics that replicate movements of human hands. But in our case, we use the "V-Sido" system on the controllers or glove-controllers, through which we process human action.

“What this system does is that it converts the hand action to robot action in a safe manner. So that's the most cutting-edge technology, that the robot movement would be safe," he said.

While the creators insist the KURATAS is designed solely for peaceful and playful purposes, its weaponry seems anything but.

The phrase "killer smile" has a new meaning with the robot's Gaitling gun (machine gun). The gun can fire 6-thousand BB bullets a minute at the smile of the pilot.

Another artillery, the external option "Lohas Launcher", shoots out plastic bottles filled with water, though it is designed to stray from its aim, thereby making it safer.

Kurata's workshop has already received over 5-thousand orders and enquiries from around the world - though unwittingly some had thought the site was a joke and cancelled their orders.

But make no mistake - their ambition to sell the robot is real, and the made-to-order machine will cost upwards of US$1.2 million (RM3.66 million).

Add-in options such as weaponry, interior design and custom colours - even a camouflage design - will all come with additional cost.

Despite the hefty price-tag, 14-year-old Shunsuke Sasaki is impressed.

"It's awesome, it's like Gundam and I want to ride it" he said, referring to one of Japan's most popular animated series featuring giant robots.

The creators have not given a timeline for when the Kuratas will go on sale, but they already have their minds set on potential clients - millionaires who want more play.

The KURATAS is on display at Tokyo's National Museum of Emerging Science and Innovation until December 10th.