Following mass Twitter Japan firings, some call for legal action

"It is generally considered difficult to lay off employees in Japan. While staff can be let go due to dire financial circumstances, companies typically need to prove they have been operating in the red, demonstrate that attempts were made to avoid dismissals and, if lay offs are called for, show that the selection process governing dismissals is carried out in a fair and objective manner."

Well, guess I'll wait for the lawsuits to take place to further inform my opinion

Despite some poking around I haven't been able to find any reliable numbers about how many layoffs there actually were. There are some rumors that the whole marketing department was sacked.

That said, the article is correct that it is difficult to legally fire full-time employees in Japan, especially with such short notice. I wouldn't be surprised if some lawsuits crop up from this.