"I didn't know how much support was out there.
"I came home for the weekend and we watched my first performance on TV - and after that my phone was going crazy, and I had 200 friend requests, all from Masterton people.
"When I'm walking through town, I still get people coming up and asking for an autograph or a photo.
"It makes me feel proud to be from this town."
Since New Zealand's Got Talent wrapped, Karaitiana has been performing up and down the North Island and working on polishing his act.
He is also now frontman of pop-rock band The Superb - who will be appearing at his King Street Live gig - sings with a four-piece R&B group, and plans to release his first single at the end of the year.
This rock'n'roll lifestyle is a far cry from Karaitiana's very first New Zealand's Got Talent audition - when the shy and withdrawn young man was grieving the loss of his sister Shanice.
His mother decided he could do with a surprise.
"At the time, I couldn't even leave the house to go to the supermarket," said Karaitiana, who had never performed in public before his audition.
"Mum decided to cheer me up and take me shopping in Wellington.
"But we pulled up to Wellington East Girls College, where they were holding the producers' auditions.
"I didn't even have a guitar on me - but they lent me one, and I played for the producers for about 45 minutes."
These days, a more confident Karaitiana is looking forward to his Masterton gig, where he and his band will be performing "everything from Bruno Mars to Pink, from Michael Jackson to the Doobie Brothers".
He will also be performing original material, including his single The Best Night of My Life - about his brother winning his girlfriend over with fish and chips on the beach.
"I'm nervous - I hope it lives up to the hype. But I feel ready for it.
"I want to have a good time in my home town - and show everyone how I've grown and matured since the show."
Cruize Karaitiana will perform at King Street Live on Saturday September 6, starting at 7pm. Tickets are available from www.dashtickets.co.nz.