It's not necessarily a comparison but you can't deny they are similar, and the most logical answer to the question that was presented. More logical than say, Gackt or SOULHEAD.
I have always struggled finding good electronic J-pop artists, as I'm quite picky (about everything). I have found some luck however with the following artists:
mini
Aira Mitsuki
Mizca
You may also check out:
Ami Suzuki (she is hit or miss a lot of the time, has a very distinct, much deeper voice when not auto-tuned)
That's all I can think of off the top of my head. Ami Suzuki uses some grittier beats but I tire of her easily. Aira Mitsuki has a grittier sound as well, if you care to explore her further.