People passing in front of Wisma Atria on Saturday were surprised by the hugs, high fives and balloons they got from perfect strangers.
It might have seemed like a Twilight Zone moment, but what really happened was that they had stepped into a "kind zone".
The one-day event was organised by 23 students from Ngee Ann Polytechnic in a bid to encourage people to be kinder and friendlier to one another.
They also felt that Singaporeans generally shy away from interaction with strangers.
Student See Seng Yang, 18, the event director, said: "We realised that in Singapore, there is not much interaction between strangers, and sometimes, people don't even say thank you or welcome.
"We hope the event can inspire people to open up and be friendlier. A simple gesture of kindness can make someone's day."
The students, who set up the event as part of a school project, also spent a day collecting about 1,000 handwritten notes from their schoolmates.
The notes - containing messages like "Do give up seats to the elderly on the bus! It will brighten their day!" - were given out to the people who stepped into the "kind zone".
Engineer Royston Lau, who had gone to Orchard Road with his family for lunch, said it was "interesting to see young people doing such things in Singapore".
His family was approached by a student who gave out balloons to his eight-year-old daughter.
Mr Lau did not feel that Singaporeans are an unkind bunch.
"I don't think anyone is unkind by nature, but maybe we are not as friendly as people in Western countries. It is just a cultural difference," he said.
Several passers-by shunned the high fives and hugs, but most were amused.
Student Gwen Lim, 19, was walking to the train station when she was approached by a student who wanted to give her a hug.
"I didn't know what she was doing, so my first instinct was to dodge," she said.
Still, the act definitely brought a smile to her face.
"I think maybe Singaporeans are not used to such things happening here yet... I know free hugs and all are quite common overseas. Maybe we just need time to warm up," she added.