"We put a notice in the daily notices and said it was for camp. They thought they were in trouble, they were freaking out.
"When they found out what it was actually for some of them cried, there was a lot of 'awws' and big smiles all round. I felt warm, fuzzy, content and happy."
She came up with the idea while speaking to a friend about Valentine's Day early one morning.
She saved hard to get enough money to buy the roses and ordered them just before the school year started in late January.
"All the smiles were worth more," she said.
Hang said she's known for random acts of kindness and being thoughtful.
"This is very typical of me," she said "[My friend] would have loved it."
Where to get help
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention 0508 050 822
If it is an emergency and you feel like you or someone else is at risk, call 111.