Students are tasked with completing five challenges: product validation, a business pitch, sales and marketing and an annual review.
Teams are judged to find the regional finalists and the winning teams represent their region in the national final.
The women developed their body wash and moisturiser business iSoaknSooth to find a solution to Toyah's 3-year-old daughter Kora-Leigh's eczema.
Kora-Leigh and Shadrach's children 4-year-old son Kadis and 2-year-old daughter Nivayaleigh-Pride were testers for the natural and preservative-free products.
Before they made the products, Toyah says she tried "everything" to help soothe her daughter's skin.
"It got really expensive and the eczema adapted to it, so I had to find a solution."
Since using it in March, Kora-Leigh's once visible and inflamed eczema has practically disappeared.
"Her face, hands and feet are clear and hydrated rather than dry and itchy like it used to be, but now it is her torso, so I am seeing results," Toyah says.
The products are made with key ingredient kawakawa - a versatile herb long used in Māori medicine and essential oils.
"Māori have always used kawakawa's healing properties and we've carried it on."
Since starting the business they have quadrupled their sales targets and received offers from shops to display the products.
The success of the business has given them confidence in themselves and motivated them to continue growing it.
They have paid all their invoices, along with the $700 start-up loan that is part of the competition package and are well on their way to achieving their goal of a $2000 profit payout by Christmas.
However, they say the money is a "bonus".
"Just that we've found a solution that works for our kids, and that is safe and natural was the goal."
They both started at the Teen Parent Unit about three years ago and have achieved NCEA levels one, two and three as well as a National Certificate in Early Childhood Education and Care. They are now working towards University Entrance.
"Being a teen parent, you can come here and feel comfortable because this is what it is made for rather than going into mainstream and trying to blend in," Toyah says.
Shadrach says, "We all work together; we are well supported and our babies are close, so we know where they are and what they're up to."
Toyah does not believe she would have had "as much motivation and support" if it had not been for the unit.
"I joined the TPU with nothing, no levels, and in my first year, I completed level one and two."
She plans to study a Bachelor of Teaching (Early Childhood Education) at EIT next year, with the hope of one day specialising in special needs.
Meanwhile, Shadrach is undecided but wants to continue with the business.
Melanie Fowler, head of the Teen Parent Unit, says she is "super proud".
"They've got busy lives with everything going on, but they've taken the opportunity and are really enthusiastic with it.
"The skills they are learning are going to hold them in good stead for whatever they go on to do."
