According to TechCrunch, the funds from SV Angel will be put towards buying secondary shares in Pinterest.
SV angel co-founder, David Lee, told TechCrunch that the $30m makes up around 2% of Pinterest's current valuation.
The company's valuation was estimated to be $1.5bn and has remained study after Rakuten's investment.
Pinterest and Rakuten's partnership aims to help the company break into the Japanese market as well as 17 other global markets
The funding will be used to help Pinterest improve and expand the site's community across the globe.
Ben Silbermann, co-founder and CEO of Pinterest said the partnership with Rakuten will help Pinterest move closer towards its business goals.
"Our goal is to help people discover things they love, by connecting people through their shared interests," said Silbermann. "Bringing Rakuten on board gives us an amazing opportunity to move a step closer to this goal."
Other investors that participated in the funding round included Bessemer Venture Partners, Andreessen Horowitz, FirstMark Captial and other angel investors.
Hiroshi Mikitani, CEO of Rakuten says the investment in Pinterest compliments Rakuten's business model for e-commerce.
"While some may see e-commerce as a straightforward vending machine-like experience, we believe it is a living process where both retailers and consumers can communicate, discover, and curate to make the experience more entertaining. We see tremendous synergies between Pinterest's vision and Rakuten's model for e-commerce. Rakuten looks forward to introducing Pinterest to the Japanese market as well as other markets around the world."
Pinterest recently launched a business arm for its site so organisations can now have their own page. The new site makes pinning from a company's website easier.
"Thousands of businesses have become part of our community, giving great ideas, content and inspiration to people on Pinterest," said Pinterest product manager, Cat Lee, about the development. "Whether it's Anthropologie sharing awesome clothes, Whole Foods sharing tasty recipes, the Smithsonian sharing fascinating collections, or Amazon making products easy to pin, many of us have been inspired on Pinterest by businesses. "We want to help more businesses provide great content on Pinterest and make it easy to pin from their websites."
Organisations which already have existing accounts on Pinterest can convert them to an account on the business site.
The business portal will also features case studies, guides and best practices to help businesses get the most out of their Pinterest business account.