“We were very nervous for our three-minute pitch because when you walk through those doors first impressions are absolutely genuine,” he told the JC.
“If you muck up your pitch, there’s no cut, start again, give it another go.
“If you muck up, you muck up.
“We were nervous, but as soon as we realised the Dragons understood the concept it was actually a very fun experience. We just really enjoyed it because we knew they were on our side. We know we are credible and we know we have a good idea.”
After their pitch, viewers witnessed something that has only happened on two previous shows during 15 series of Dragons' Dens – with all five judges, all successful entreprenuers in their own right, making offers on the two Pouch co-founder’s request for a further £75,000 worth of investment into the business in return for a 15 per cent stake.
Dragon Jenny Campbell offered the full £75,000, followed by Touker Suleyman, Tej Lalvani, and Deborah Meaden who also offered all the money, but for 20 per cent of the business.
Finally, Peter Jones was willing to offer the £75,000 for 25 per cent equity.
The free tool works as a plug-in for your browser and alerts you to active discount codes whenever you visit an online shop.
Pouch claim the tool will save consumers 10 per cent of the cost of every purchase they make with it.
There are currently around 3,000 retailers on board, including Topshop, Nike, ASOS, Argos, Ocado and The Body Shop.
“We worried whether these multi-millionaire Dragons had ever used voucher codes before, and whether they understood the experience, “ said Mr Plein.
“Once we knew they related to it we thought great the model works and we can talk about everything we have done so far.
“I think they liked the fact that we weren’t’ asking for a massive amount of money as well.”
After winning over all five Dragons, Mr Plein and Mr Corrigan were faced with a split-second decision on what to do next.
They returned with a counter-offer asking for three of the Dragons - Mr Suleyman, Mr Lalvani and and Ms Campbell - for £75,000 for 18 per cent of the business, split equally at 6 per cent for each of them.
It proved a winning formula.
“We ignored Peter Jones because we thought it was insulting that he expected 25 per cent of the company,” explained Mr Plein.
“We basically wanted people with retail experience – we wanted Tej because he said he loved technology.
“And we wanted Jenny because she had more time on her hands than the rest.
“The way we split the offer between the three of them just made sense really. “
During Sunday’s show Mr Plein explained he was drawing only £500 a month from the business and was still living at home with his parents.
He quit a job at Ernst & Young, having qualified as an accountant after studying economics and mandarin at Nottingham University, to concentrate full time on making his Pouch start-up work alongside Mr Corrigan, and another co-founder Vikram Simha, who did not appear on Dragons' Den.
Pouch was founded with £18,000 worth of savings but now has the potential to become a multi-million pound venture as a result of BBC exposure.
They landed the Dragons Den slot after the show's producers spotted an article on the company on an online start-ups publication. The team were invited in for an interview in February and were given the green light to appear on the show in May.
Mr Plein is also hopeful that after landing a lucrative Dragons Den deal he will soon be able to think about moving out of home and buying somewhere himself.
He says he remains connected to the community, attending Alyth Gardens shul on High Holy Days, and insisted: “I only ever date Jewish girls - it’s easier to explain what Shabbat is that way!”
This article has been amended to correct an error - we named Deborah Meaden as one of the investors.
Watch the whole episode on BBC iPlayer here (available until September 19)
