A man wearing a woolen hat, his face covered by a surgical mask, leaped over the fence of the elementary school yard in suburban Tokyo and brandished a knife at the junior high schoolboys playing there.

"What are junior high boys doing here? This is an elementary school," Friday (2/15) quotes the mysterious man as saying.

Startled, the eight schoolboys were too scared to move. The mysterious assailant waved his knife about and demanded the group's leader reveal himself. When the boy did so by running away together with another of the young lads there, the mysterious stranger snatched hold of another teen.

"Now," the weekly quotes the stranger saying to the boys, "Take off your pants."

Terrified, the young schoolboys obeyed, only for him to bark out another command.

"Now your underpants!"

The boys initially refused, but the mystery man grabbed one of them and ran his knife along the child's neck, drawing blood. The boys quickly removed their underwear.

Once they had stripped half-naked, the mystery man gathered up the teens' underwear and trousers, forming a bundle that also contained two mobile phones and 5,100 yen in cash. His arms laden with booty, the mystery man fled the scene on foot.

In his rush to get away, however, the mystery man dropped his glasses in the schoolyard. They proved the key to tracking him to his apartment, located just across the road from the school where the incident had occurred.

Police were shocked to discover the mystery man who'd allegedly robbed the schoolboys of their trousers and underwear at knifepoint was Takayuki Yamamoto, a 28-year-old sixth grade teacher at a public elementary school in the Tokyo suburb of Hamura.

"Most of the media reports of the incident made him out to be a pedophile teacher because he stole the boys' underwear and used one of the mobile phones to make prank calls to one of the boy's homes, but the reality was actually a little different," a news desk editor from a national daily tells Friday. "Apparently, what happened was that he was annoyed by the noise the kids were making outside his home, but he thought because they were junior high students they wouldn't listen to him, so he took a knife out with him to scare them. He says he stole their pants off them as a punishment."

The principal of the school where Yamamoto taught was astonished by the development.

"He told me how he wanted to work with kids for the rest of his life, so never wanted to have to take on a desk job or become a principal," the head of the school tells Friday. "He was an incredibly enthusiastic teacher, he even got in with the kids during recess to play dodgeball."

During the school's practices for a dancing competition, Yamamoto was a standout for joining in to dance along with the pupils, while his colleagues merely stood by and barked orders. Many remarked on his keenness for teaching.

But Yamamoto did have a darker side. Residents tell horror tales of how he frequently screamed obscenities at the top of his voice and threw things around his apartment, even though he never appeared to booze. His tantrums behind closed doors caused enough concerns among his neighbors that some complained to their landlord about him.

Nonetheless, the general opinion of Yamamoto was that he had been an excellent teacher since receiving his first appointment back in 2004. But one of his former students suggests the stress of looking after kids make have been a bit much for him.

"If you did something wrong, he'd tell you off, but I never heard him scream at anyone," the past pupil tells Friday. "But I get the feeling he was trying too hard to be cheerful all the time and held in what he was really thinking. I guess he must have been really stressed out." (By Ryann Connell)