A DECORATOR with a triad background was yesterday jailed for 12 years for raping a 12-year-old girl and inciting two teenagers to attack her. Chan Chow-shing, 23, now serving a three-year jail sentence for claiming to be a member of a triad society and inducing a person to become one, had been found guilty by a jury of six rapes and one charge of indecent assault. The two teenagers, Kwok Chun-hung, 16, and Lam Chi-fai, 19, assaulted the girl under Chan's order. They were both convicted of one count of rape, and were both sent to a training centre by Mr Justice Bewley. Mr Justice Bewley said the incidents must have been horrific for the girl. Although she suffered no injury, she was assaulted and threatened. While Chan was certainly young, he was the leader and the instigator and was fully mature, he said. Youth was not a mitigating factor in his case. In Kwok and Lam's case, it was a single act of rape and no violence was used, said Mr Justice Bewley, accepting that they were obviously under the influence of Chan and did what their ''big brother'' asked them to do. The court heard that the girl met a group of youths in a video game centre she had frequented since May 1991. On August 14, that year, she had tea with several of them including Chan and Kwok before they took her to a flat on the Choi Hung estate where she was first indecently assaulted by Chan. Between then and August 17, she was taken to various premises where she was raped four times by Chan who also incited Kwok and Lam to assault her. Counsel for Chan, Mr Andrew Raffell, accepted that the disparity of age between his client and the girl was enormous. While he was not trying to belittle the offence, this was not the worst of its kind, he said. Ms Esther Toh, for Kwok, said her client was only 14 1/2 at the time of the offence and being a person of a weak character, he was obviously under the influence of Chan. Lam's counsel, Mr Michael Ko, pleaded for leniency on behalf of his client and asked the court not to send him to an adult prison as he was just 17 at the time.