According to the website, the maintenance is finished (http://onigiri.cyberstep.com/info/topic/maintenance/19522).
However, when trying to start the game, the launcher and the client update, then the login screen states:
'ERR_01007
Currently in Maintenance'.
As I said in a previous post, fire your amateur IT staff and hire actual professionals...
Update:
Trying again a bit over 30 minutes later, still '... in Maintenance'.
My educated guess is that those nincompoops left the server on a 4 or 5 hours timer to get back online...