Japanese economy minister, Yasutoshi Nishimura, speaks after meeting with the government's expert panel earlier

The argument by the government is that calling for a state of emergency isn't going to spur a massive change as they can only request citizens to stay at home and follow precautionary measures, but not legally enforce them.

That said, I'm sure there are a lot of reasonable people out there and if the government is seen to be taking this seriously, offices and businesses will also shut shop to follow the government's request to try and curb the spread of the virus outbreak.