Initial magnitude is referred as a JMA magnitude in the e-mail. You will also find qualities in the table. Upper table is the information provided by JMA and the lower table is the result of the analysis. Strike is the direction of the fault measured from clockwise to the north. Dip is the dipping angle of the fault measured from horizontal plane.
Rake is the slip direction on the fault measured from anticlockwise to the horizontal plane.
The focal mechanism gives you two possible fault planes and either of them is an actual fault surface. Mo is moment, whose unit is N m. Mw is the magnitude measured from moment release. VarRed is variance reduction, which is the same as quality mentioned before. The variance reduction is defined as an index of a waveform fit between observation and synthetic waveforms.