Product review (3 stars): Works well enough, but can be a little off.
I cooked a few pounds of Barilla linguine in it, in a small 700w Panasonic microwave.  I mention the container was slightly too short for the pasta, and slightly to long for the microwave.  The linguine sat at an angle and the container could only turn about 90 degrees.  Luckily it was a microwave that reverses direction.
That said, it actually cooked the pasta with no issues (except the first time, when I put the cover on and it boiled over.  Messy.  Don't cook pasta with the cover on).  In my machine, total cook times (starting with cold water) were pretty close to stovetop, maybe 2-3 minutes less.
Mostly I just use tupperware now, and accept that my pasta will be half-length.
If short pasta bothers you, this might be a good purchase.  If things not fitting quite right bother you, it might not.

And yes, everything on it is in (I assume) Japanese.  But given the variation between microwaves and altitudes, it's going to be a matter of trial and error anyway.  I suggest:
1: fill about 1/3 to 1/2 way with just water, or water and salt.  Bring to a boil (1.5-3 min, ymmv)
2: add pasta, oil if desired, cook for 3 minutes less than recommended (on your pasta packaging) time.  Cook at power 7 if 1200w, power 5 if 1500w.
3: taste; cook in addition 2 minute blocks as needed; write down your final time.

Or just wing it and live with the results.  If you're using this I assume you're not feeding a family.