The 32-page book, illustrated by Christine Luiten, is aimed at five to 10 year olds and if they get their funding, will be released on National Coming Out Day on October 11.
The main thread of the book is a bi-racial love story between two male characters, but Mr Harris said the book is relevant straight children as it presents them a positive "happy ever after" storyline and normalises gay relationships.
"I think the main thing is both of us grew up without any representation in storytelling.
"We looked at all the fairytales that existed and they are all heterosexual. And all the movies you go to see, they are all heterosexual. We grew up with the sense of being invisible."
Mr Harris said both he and Mr Reynolds were bullied for being different and, while he knew one book wouldn't change that sort of behaviour, it was start.
Mr Harris would be delighted if schools were to buy copies, believed to be the first New Zealand children's book to have gay characters at the forefront, but said they couldn't be forced to.
"It's really for parents. They can be heterosexual parents as well that want to show their kids different kinds of relationships.
The authors have received positive responses so far, especially at the Out in Park Wellington pride celebration last month, where they had a stall.
"A lot of people were coming up and getting quite excited. It was a really cool reaction obviously a friendly crowd."
If Promised Land gets published, Mr Harris said the pair might think next about writing a story with a trans storyline.
Where the money will go:
• Illustration costs: $16,000 for 32 full-colour illustrations
• Design/layout: $2000
• Printing/reward costs: $5000
• Kickstarter and payment processing fees: $3000.