Guardian HQ missions

[Strippervicar]

Sorry for this very n00bish question, I have been playing since the game's european release, and am now level 18, but there is one thing I still don't fully understand. Up until I was level 17 there were no missions I could accept from the Guardian HQ, then the one with the girl in the mask came up. Do missions appear here according to your level? Or are they activated in some other way?
Thanks very much in advance to anyone who can explain this to me!

[Skids]

The guardian HQ missions appear base on updates by sega. US wise. Alot of player regardless of level were able to access it last thursday when sega did their weekly updates.

[Strippervicar]

ah I see, so the next mission could come at any time? Thanks!