Thing about level grinding is that Onigiri don't have the Everquest/Star Wars Galaxy/Ragnarok way of grinding where it was friends, good gear, hats and/or exploration first, levels second.
Onigiri is a theme park MMO where you're on a rail throughout Japan to kill some guy with big hands, and by the time you did all your stuff for said town and field, you can't grind very well and you're getting killed by a poorly animated and weird looking dragon, and if you have any eggs left, a demonic bishonen dude. Good luck getting to Kanto.