School bus-yellow, four feet tall with almond-shaped alien eyes, Wakamaru turns his head and greets the schoolgirl, who, giggling, shakes his cupped, plastic hand - stooping slightly to make eye contact. Around her, her peers stare open-mouthed.

The robot senses the IC-chip identification of the schoolchildren swarming around him and memorises their faces. Those without necessary ID are confronted, photographed and news of their presence is relayed instantly to the relevant authorities.

Wakamaru - Mitsubishi's 'partner' robot, a humanoid machine to assist at home or in service industries - isn't the most threatening security guard in the world.

Wakamaru couldn't stop the 2001 massacre of eight children at a school in Osaka by a knife-wielding attacker, or the murder in June of a 7-year-old in Akita Prefecture. But Wakamaru, standing sentry at the entrance of Setagaya Elementary School, boldly emphasises the Japanese faith in technology as a logical, calculable salve to the whirling illogicality of human society.

"The Setagaya school's use of Wakamaru was an interesting and bold experiment," considers Timothy N. Hornyak, author of the new book Loving The Machine: The Art and Science of Japanese Robots. "I expect robot sentinels will become widespread once safety issues are addressed and AI abilities improve."

"There is very little cultural baggage in Japan regarding adopting robots as everyday partners, tools and friends," he continues. "This is clear as day on the faces of the children themselves."

Wakamaru isn't the only robot stationed in Japanese schools, but he is the first robot posited as a solution to an urgent societal problem rather than those embedded in schools simply as part of an academic diorama.

In a Nara elementary school, Dr Hiroshi Ishiguro - the famous inventor of the disquietingly lifelike Repliee female android - observes as Robovie, Ishiguro's bug-eyed Short Circuit-esque creation, attempts to fathom the arbitrary nature of friendship - striving to integrate via games of paper-scissors-stone, hugging, singing and confiding secrets in the children.

Across the globe, in San Diego, QRIO - the posterboy for Japanese robotics - nimbly twists, turns and jumps, dancing with toddlers and copying their exuberant moves. Next door, Sony's Fumihide Tanaka and the University of California's Professor Javier Movellan eagerly record the kindergarten children hugging and kissing their robot teacher, RUBI - placing a blanket over the robot's bulky frame and putting her to bed as her battery runs low.

"I am convinced that educational robots do have a role in early childhood education," Professor Movellan tells me, when I question the practicality of his technology. "That much I can say. Children just love them and I think they will become a fantastic tool for teachers and parents."

Movellan's RUBI/QRIO project with Sony is the most in-depth immersion of robots in an educational environment so far. The long-term goal of the project is to investigate and improve human-robot social interactions.

Crucial to the advancement of humanoid robots is for robots to be able to comprehend human social interactions. Japanese researchers found school environments perfect for studying how humans learn, interact and form relationships at a basic level. As the findings of these experiments are fed into the design of the robots, inevitably robotics research is throwing back complex sociological feedback on the formative stages of human relationships.

The first school-robot study was Ishiguro and Kanda's 2004 work with two English-speaking Robovies in a Japanese elementary school. The humanoid form provided a point of familiarity for users, and enabled the machine to replicate necessary social signals: looks, gestures, movements. The researchers noted the children's English test scores improved as they associated with the robot.

However, they found that the children's interest in the robot waned after a few weeks, due to the limited potential for interaction.

"More interactive behaviours are needed," Ishiguro acknowledges. "And the robot needs to have a role in the school. But the strong aspect is that the robot can know the human relationships among children by using the ID tag system. This means the robot can learn social behaviours."

Subsequently, Robovie was programmed with 'pseudo-learning', whereby the robot would reveal more functions, including pre-programmed 'secrets', to a child as their relationship progressed. This allowed the children to bond with the robot - increasingly treating Robovie as a peer rather than a machine.

The QRIO/RUBI project takes these experiments as a point of departure - even borrowing Robovie's head for RUBI. Javier Movellan noted that children were scared of Robovie, so the machine was revised to include more humanised characteristics - a plumper, less mechanical frame, with appropriately changing facial expressions and fibre-optic hair that changes colour to denote mood.

The metallic space child QRIO joins the children in a daily dance session, while children interact with RUBI in a learning capacity, using a touchscreen embedded in her belly.

"QRIO was pretty much treated like a special classmate," Movellan says. "The children called QRIO 'Baby QRIO' and RUBI 'Mama RUBI'. Initially children were apprehensive to interact with QRIO but started hugging RUBI from day one. We made QRIO less threatening and we made RUBI more lifelike so they treated her like a teacher."

Movellan and Tanaka were looking to create an empathic system based on intuitive, non-verbal contact. They wanted to develop a robot that could read and understand a child's emotion, and react with an appropriate response.

"The expression of emotion is critical for child-robot communication," the professor insists, dismissing AI's focus on congitivism. "I see language and thought as a very simple trick that operates on top of a very sophisticated operating system that is fundamentally based on emotion and affect. This belief is critical for the RUBI project."

Why is it necessary for a software-driven teaching-aid to have a capacity for empathy?

"It is important for social interaction robots to interpret and express emotion," Movellan answers. "Humans are simply wired that way. Whether robots need to have emotional systems is an open question. The problem is that we don't know what emotions are for from a computational point of view. I suspect they have to do with coordinating adaptive behaviour at multiple time scales."

The most illuminating results from phase 1 of the project have led to the ongoing development of RUBIOS, a revolutionary new operating system which attempts to emulate a crucial human component - our ability to deal with uncertainty.

"Traditional OSs are designed to rapidly distribute processing resources to accomplish fixed tasks," Movellan explains. "In social interaction, however, the tasks need to be continuously re-evaluated. The OS needs to drop tasks, if necessary, or to create its own tasks. This is not really part of the standard OS make up. What would you think of a personal computer that decides not to do some of the things we ask it to do, or do something else instead? Yet I believe this is very important for systems that operate socially with humans.

"Most importantly, instead of us programming each module, we simply tell it when to feel good and when to feel bad. We then let learning algorithms figure out how to accomplish those goals. We call the approach 'Intention Programming'."

The RUBIOS is a tangible by-product of children-robot interaction, which has developed only by actually incorporating the children into an almost open source co-developer/debugger role.

"I really think we are turning AI upside down," regards Movellan. "Instead of focusing on abstract intelligence and chess, AI should have focused on understanding adaptive behaviour and daily life."

Despite this, the potential practical applications of children-robot studies remain largely nebulous. QRIO may have become a dance star on YouTube videos, but his real commercial potential was lost even on Sony, who recently closed development on the robot outside of the RUBI project.

"The robot can be a help for teachers in the classroom," Fumihide Tanaka told me, defending his childlike silver pal. "For instance, QRIO can promote children's physical exercise such as dancing."

So, however, can PE teachers and Dance Dance Revolution.

Currently no technology has been sufficiently developed to fulfil the role of a robot teacher, or other autonomous partner robot in society. Nevertheless, in Japan, new schemes are unveiled constantly. Many of these, however, scan mostly as advertisements for their developer's ingenuity - with Wakamura's high-profile ineffectuality a particularly shiny band aid slapped on a problem demanding compassionate, human solutions from its society.

"I don't think anyone believes robotic security is currently very practical in this area," agrees Tim Hornyak. "Because of the country's post-war recovery through manufacturing, Japanese are more predisposed to considering and embracing engineering solutions, but it's not a case of ignoring the human factor."

The RUBI project remains exciting as it gathers momentum - its function determined by its pre-school co-authors - branching off into genuinely fascinating sociological studies. It expands the existing Japanese research into more practical areas, while riffing on a sentiment that has permeated Japanese technology, fiction and popular culture since the Edo-period clockwork automatons - the humanisation of technology.

"I think the mistrust of robots in the US is healthy," considers Javier Movellan. "I see it as healthy scepticism about the value of robots. My experience is that when people in the US see the potential of this technology they in fact provide ideas on how to make it more useful.

"Japanese culture is more comfortable with the idea that every existing thing, including inanimate objects, has a soul of some form," Movellan emails. "Western religions are not comfortable with the idea of 'giving life' to a machine. The problem with this type of explanation is that it makes sense but it is probably wrong ;-)"

Paro actually has an entry in the Guinness Book of Records for being - officially - the cutest robot in the world. The star of a new film by Danish director Phie Ambo, Paro snuggles and squirms adorably with old people, hospitalised children, and even the Japanese Prime Minister. The cuddly baby harp seal - which took 12 years to develop - is a 'Mental Commitment Robot', whose function is to relieve stress and boost cognitive functions. Studies involving Paro's interaction with brain damaged subjects has shown, incredibly, direct results in improved brain function.

PEBBLES isn't really a 'robot', but the 'teleprescence' technology has been developed using the same anthropomorphic principles as social robotics. PEBBLES is a tool for hospitalised children to maintain a presence in their classroom. The PEBBLES robot sits at the child's schooldesk, its round 'head' displaying the child's face - raising its hand if the child has a question. Meanwhile, the sick child controls the robot from a control unit by their hospital bed.

"By calling PEBBLES a robot - people immediately get it," designer Michael G. McHale explains. "We do however comply with Bob Schrieb's addition to Isaac Asimov's Three Laws of Robotics: 'Never build a robot without an off switch.'"