All 1,000 models of the robot, which knows whether you are happy or sad, sold out at the consumer launch in Japan.

For £1,000 plus a payment of £125 each month for data and insurance fees, Pepper can tell whether you are happy or sad.

It is designed to interpret emotions by analysing the tone of voice and facial expressions to interact with human beings.

The robot was built as an emotional companion for people, and is equipped with cameras, touch sensors and an accelerometer.

SoftBank Robotics Corp, which created Pepper, explained the robot's overarching aim: "He tries to make you happy."

The SoftBank spokesman added: "Pepper is at ease when he is with people he knows, happy when praised and scared when the lights go down."

The automated companion can speak English, French, Japanese and Spanish, with more languages added in the coming months to the robot's app store, which has more than 200 pieces of software.

The company says the robot will make mistakes and learn from them.

It won't do your house work, say the company but has conversation abilities, analysing emotions, developing its own opinions and retrieving information such as mail and weather from the internet. Pepper also utilises voice and touch to understand verbal and non-verbal cues.

SoftBank CEO Masayoshi Son said: "Pepper will become smarter every day by itself."

He added. "Hundreds of thousands, million[s] of Peppers in the future, will teach each other and learn from each other simultaneously."

Future uses of Pepper include the building of a larger machine for corporate use. The robot could become a basic receptionist or provide other customer services.

In December, Nescafe hired 1,000 Pepper robots to work across home appliance stores in Japan, where they helped customers looking for a Nespresso coffee machine.

The company will announce at the end of July when it will sell the next batch of the robot.