J0. = Yo.
t3h = the @ = at sensei = teacher -san = standard Japanese name suffix, shows politeness th4z coo = that's cool
msg = message
Piro tweets: here's a screenshot of the first frame: http://tinyurl.com/3t7eb5
Piro tweets: (it should be noted that Junko doesn't look like she's troubled, at least not on the surface.)