Justin Kan's new legal startup, Atrium, has snatched up $65 million in a new round of funding led by Andreessen Horowitz.

Kan is perhaps best known as the creator of modern live-streaming with the launch of Twitch, which sold to Amazon for nearly $1 billion. He aims to repeat his success with Atrium.

Andreessen Horowitz's Andrew Chen said Kan's boldness is part of the reason the investor has so much faith in Kan as a founder.

Justin Kan was unable to sell Andreessen Horowitz, one of the most powerful venture capital firms in Silicon Valley, on investing millions into his nutty startup Justin.tv more than a decade ago.

"We couldn't get them to invest in Twitch," Kan said, referring to the live-streaming platform's spinoff that's focused on video gaming. "Actually, I don't think I ever got a meeting."

But now, years later, the firm is leading a new $65 million round of financing for Kan's new startup, Atrium. The legal technology startup builds software tools for an in-house law firm whose attorneys specialize in helping startups do the things all successful startups do: raise funding, issue stock options, and create commercial contracts.

Someday, the startup could bundle these software tools, which use machine learning to understand legal documents and then automate certain processes, and license them out to law firms.

Marc Andreessen, one of the most influential investors in the Valley, and the firm's Andrew Chen will join Atrium's board of directors.

Ashton Kutcher's firm Sound Ventures, General Catalyst, and Y Combinator, whose CEO and partner Michael Seibel will also join the board of Atrium, signed on as co-investors in the round.

Chen met Kan about 10 years ago, when the young entrepreneur hatched an idea for a live-video platform that streamed his life 24/7. He strapped a camera to his baseball cap and wore a backpack filled with cellular data cards that carried whatever he saw to the web.

"The idea was creative, but so off the wall," Chen told Business Insider. (Even Kan would later call the startup a "terrible idea.")

Justin.tv pivoted and pivoted again, transforming into the world's largest live video platform. Twitch sold to Amazon for $970 million in an all cash deal in 2014.

Chen credited Kan with "inventing modern live-streaming." His boldness is part of the reason Chen believes in Kan as a founder.

In 2017, Chen joined nearly 100 institutional and angel investors in providing $10.5 million in Series A funding to Atrium. He must have been impressed, because he convinced Andreessen Horowitz to put in more than half of the $65 million round total for the Series B.

In the last year alone, Atrium has offered its legal services to over 250 startups, who have raised a total of $500 million in funding. Its client roster includes digital pharmacy startup Alto, scooter-sharing firm Bird, and fraud detection software-maker Sift Science.