Yes, text messaging in Japan is fragmented. Its often impossible to text between carriers and my Japanese carrier offered no capability to send or receive texts overseas.
When the earthquake hit power and phone service became largely unusable pretty quickly (somewhere between Tokyo and the quake). However, I was able to send a facebook post from my Japanese style smartphone that hit a fair number of my friends and family telling them we were OK before everything went down. I rarely used it for day to day stuff since it wasn't all that useable, but for this application is was perfect.
Not to mention the Yodobashi camera store (more of a complex really) in Shinkjuko will blow your mind.
Yeah, the word is: here maybe 4PM.
Here in Tochigi it was strong, but not frightening. My first time under a table! Lots of stone walls fallen over in my neighborhood.
According to wife, supermarkets are rather bare today.