While he hoped to win a seat, he said he couldn't believe the news and said his family were beyond happy for him as well.
Wang joins Mercia Yates, Sandra Kai Fong and Reynold Macpherson as the district's four new councillors.
Councillors Rob Kent and Mark Gould have missed out. All other incumbent councillors were re-elected.
Progress results have the elected councillors as Tania Tapsell with 8707 votes, Raj Kumar 8640, Sandra Kai Fong 7936, Mercia Yates 6925, Peter Bentley 6630, Merepeka Raukawa Tait 6474, Fisher Wang 6172, Reynold Macpherson 5877, Dave Donaldson 5350 and Trevor Maxwell 5343.
Chadwick said it was good to see a diverse council.
"It's a very good council and reflective of the diversity in the community. Those challengers who are elected into council are going to learn the complexities of making balanced decisions and that's not a bad thing.
"We hold the majority too and that's important. It's not a bloc it's those that see we've got to keep this district moving."
About 40 to 50 people were at an election party at her home.
She congratulated Mercia Yates, who was present at her home, and Fisher Wang.
"Wang is a young guy with integrity. When he struggled with billboards I contacted him and said get used to politics. It's not a nice game but it's how you handle that.
"How exciting our district has chosen someone who's 19. We're going to be the talk of New Zealand.
"To Mercia well done. It's wonderful you're here for all of us to share. People wanted a positive team and that's what's so affirming. They want to keep the place going ... that's what's been delivered.
Dave Donaldson and Trevor Maxwell are both fewer than 200 votes ahead of the first candidate to miss out, Patricia Hosking. She sits at 5180 votes and that could change once special and late votes are counted.
But Donaldson was confident the votes would not swing out of his favour.
He said he and his wife had cast special votes and special votes had previously been in his favour.
"I look at this and think we've got a positive council ... "I look forward to all 10 councillors making a positive contribution."
The four mayoral candidates were Stephanie (Steve) Chadwick, Dennis Curtis, Rob Kent and Reynold Macpherson.
A total of 34 people stood for the 10 seats on the council. They were: Peter Bentley, Liz Carrington, Richard Collins, Kevin Coutts, Brendan Davis, Alan Deverson, Dave Donaldson, Mark Gould, Ryan Gray, Bill Hedges, Trish Hosking, Peter Jones, Sandra Kai Fong, Rob Kent, Julie Kerry, Raj Kumar, Reynold Macpherson, Matthew Martin, Trevor Maxwell, Lachlan McKenzie, Lance Mutlow, Oscar Nathan, Conan O'Brien, John Rakei-Clark, Merepeka Raukawa-Tait, Linda Rowbotham, Harina Rinaha Rupapera, Alan Tane Solomon, Kaya Sparke, Tania Tapsell, Shirley Trumper, Fisher Wang, Bam Whare, Mercia Yates.
Elected members were Peter Bentley, Dave Donaldson, Sandra Kai Fong, Raj Kumar, Reynold Macpherson, Trevor Maxwell, Merepeka Raukawa-Tait, Tania Tapsell, Fisher Wang, Mercia Yates.
Seven people stood for the four vacancies on the Rotorua Lakes Community Board. Nick Chater, Sandra Goodwin, Jennifer Rothwell, Phill Thomass have all been elected.
Six people stood for the four vacancies on the Rotorua Rural Community Board. Bryce Heard, Ben Hollier, Sarah Thomson, Shirley Trumper have all been elected.
This result is based on the counting of approximately 95 per cent of the returned votes.
The progress result does not include some special votes and votes returned today that are still in transit to the processing centre.
The outcome of these elections may change once all votes have been counted.