SINGAPORE - What began as a case of a teenage boy trying to befriend a girl took a nasty turn, with the boy getting assaulted, threatened with extortion and having his money taken.

Orchestrating the attack on the boy was a 17-year-old who had called him for a "settlement talk".

It started in October 2016 with a 15-year-old boy asking a girl, also, 15, be his girlfriend.

When the girl, a China national, rebuffed him, the boy turned aggressive and called her a "prostitute". He also kept pestering her.

The girl complained to Wang Zhen, 16, also a China national. Wang, in turn, approached Bryan Lim Jun Ying, 17, to tell him what the boy had been up to. This was to be the start of the boy's nightmare.

Wang arranged for the boy to show up at Causeway Point on Dec 27 last year. Lim, who was armed with a knuckleduster, and nine others were waiting for the victim there.

The boy was told to follow the group to the carpark at Level 5 where Lim punched the boy and another person named Jason - who has absconded - punched and kicked him.

Bleeding, the boy managed to flee.

That evening, Lim called the boy and told him to bring some cash to "resolve any outstanding problems between them''.

When the two met at a coffee shop in Choa Chu Kang, Lim demanded $100 from the boy. This was supposed to be a form of apology to the girl and the victim paid out of fear.

Lim then said the "boss'' of his gang wanted the boy to pay $10,000 for ruining its reputation, or the "boss'' would "chop off his arm''. He asked the boy to cough up $5,000 by end-February, saying he had paid the balance on his own.

Lim also extracted $400 from the boy to get the girl to forget the matter.

On Jan 4, 2017, the boy ignored Lim's text message to meet. The next day, Lim and five others went to the victim's home and asked why he was evading them. Lim took $250 from the frightened boy and also his $2,499 laptop.

When the victim begged Lim to return his laptop, Lim hit the wooden table with an extendable baton and damaged it. He also got Wang and two others to punch the boy.

In a separate case, Lim stole three items worth $18 from Giant supermarket in Woodlands on June 2, 2016.

In sentencing him to reformative training on five of 10 charges on Friday (Dec 29), Community Court Judge May Mesenas reprimanded Lim for using his size to intimidate people.

She said despite a guidance programme in 2015, he had not learnt his lesson and, instead, gone on to commit very serious offences.

She allowed his lawyer's application to defer sentence until Jan 12. She increased his current $15,000 bail by another $5,000.