"It's pretty cool -- I didn't expect to get the people's choice award," Joseph said.
"Going to college was a big step -- he was really nervous and wanted to focus on his schoolwork," his father Pano added.
"He wasn't confident about continuing with chess but he thought about it and said, 'yeah, I'll do it'."
Chess for Joseph is a family affair, with Pano having played competitively as a teenager.
Joseph said he was always intrigued by the chess board his father kept on the coffee table.
"I was bored and asked Dad if he'd be able to teach me.
"We had a game every time it was raining and there wasn't much to do."
"If he lost, I'd always ask him, 'now, do you know why that happened?' Pano said.
"He ended up beating me the other day -- he can now see about seven moves ahead."
Joseph eventually joined the South End school's chess club, becoming a regular fixture at the annual Carterton Schools Chess Competition.
He and the South End team later went on to compete at Chess Power's national schools' tournament.
This has been Joseph's first year competing individually at both the Wellington regionals for the New Zealand Interschool Chess Competition -- where he came first overall -- and at the national finals in Auckland.
Joseph said the national competition was nerve-wracking, especially being up against Year 12 and 13 players.
"It's very serious and formal -- you've got people walking around in blazers and suits.
"But once you get into the game, it doesn't feel so hard."
Pano said Joseph has had some hair-raising moments while playing -- with some of his wins coming down to the wire.
"He was playing this one guy who had taken most of his pieces and still had a couple of minutes on the clock, but Joseph only had about 30 seconds.
"Then, Joseph check mated him with one second left.
"He's had a battle on his hands, as he's been up against some talented kids, but he's excelled."
Joseph said the key to chess is "using the right mix" of attack and defence.
"You have to really concentrate, and be prepared to make sacrifices."
Joseph will start at Wairarapa College next year and plans to continue with chess.