I've lived in Japan for nearly a decade and never heard of anything like it. However it seems legit: domain name was registered in 2012 with a Japanese registrar and was renewed in 2015. The company (from their website) claims to have operated since 2010.

It's worth noting that most Japanese people would find this a pretty weird thing, I think -- it's not normal. I can't imagine that it would actually work out well if you got found out.