It all started with the messaging app Ms Cheryl Foo, 29, and Mr Alex Wee, 32 used to chat with each other when they started dating.

The couple liked the virtual stickers that came in the popular chat app Line, and Ms Foo took a special liking to Brown, the bear character with a perpetual downturned smile.

When Mr Wee saw the Line pop-up store outside Wisma Atria last week, he devised a plan to pull off a surprise wedding proposal to Ms Foo with Brown's help.

On Saturday, Ms Foo was led to the store by her sister, 26-year-old Clarissa. The two stood in line for about 10 minutes, waiting to take photos with the mascots of Brown and Cony the rabbit, two popular characters from the app.

But when it came to Ms Foo's turn, staff started to flash placards at her with messages that read "To me you are perfect" and "I hope by now you understand how much you mean to me".

The bear mascot then removed its costume, revealing Mr Wee underneath. He then presented a wedding ring to Ms Foo, who by then was moved to tears.

Her family members, including her parents and 28-year-old brother Desmond, appeared at the scene, cheering and taking photos.

The couple were introduced to each other four years ago via a mutual friend, and have dated for six months now. They will tie the knot on June 1 at Yunnan Garden at North Buona Vista Road.

They had taken their wedding photo shoot in late April, but Mr Wee, a communications management executive, still had not proposed.

"He told me that he would propose to me before our wedding, but as our wedding day is nearing I thought there would not be any proposal anymore," said Ms Foo, a nurse.

Mr Wee said it took him a week to plan the surprise, with the help of Ms Foo's family and his friends.

"I told her I would propose to her before our wedding photoshoot, so I'm actually already late by two weeks," he said.

"Each time I met her, I would tell my friends not to message me about the surprise proposal, in case she saw. I had to delete all the messages too."

Ms Foo's sister Clarissa, who took her to the store, said: "I lied to her that the mascots were going away after this weekend, and that I really wanted to come and see them. She liked them too, so she agreed to come."

The Line pop-up store, which will sell merchandise of the characters, will be outside Wisma Atria until May 22.

Character mascots will be at the store from 1pm to 5pm every Saturday and Sunday.