As Slack ramps up its investment in Asia, Toss Lab, the South Korea-based creator of enterprise collaboration platform JANDI, is preparing to become a more formidable rival. The startup announced today that it has raised a $13 million Series B led by SoftBank Ventures Asia, the early-stage venture arm of SoftBank Group. Participating investors also included SV Investment, Atinum Investment, Must Asset Management, Shinhan Capital, SparkLabs and T Investment. Founded in 2014, Toss Lab said the round means it is the first Korean company in the collaboration space to raise over $20 million to date.