Japanese company Cerego, the brains behind the social learning platform iKnow!, has raised $3.4 million in a round of funding from NTT DoCoMo, Japan’s biggest mobile phone carrier. To date, Cerego has raised a total of $23.4 million in funding since its launch in 2000. Cerego originally launched iKnow as an online service for Japanese people to learn English and then expanded the platform to allow