User blog comment:Angel Emfrbl/Well its definitely official/@comment-26116982-20150518012902/@comment-32500188-20150524120224

@Kajiki: Like Dizzy said, it was never a secret. Those who follow Jin closely outside of his VOCALOID works know that the RL ONE is one of the singers he's associated with during his live concerts. Look up "Live in Mekaku City" and look for the female singer with the rockin' hood. That's CeVIO ONE's VP. ;-)

Lia and ONE may have similar vocal ranges, but you can definitely tell their voices apart. It's no attempt to make "CeVIO IA" and all, like a lot of people initially thought when ONE was first introduced. (Even me, before I started researching upon her after seeing her intro in IA's 3rd Anniversary live broadcast)

I was kind of hoping to catch some info as to why they're venturing forward with CeVIO on the recent release live broadcast Friday morning, but I kept getting knocked off the que and missing huge chunks of interviews. (...plus I came in on like the second half because my early alarm didn't go off, and if you don't timeshift before the event starts, you don't get another opportunity unless you're a premium NND user...) Guess it'll still remain a mystery... unless I muster up the courage to ask on Twitter myself. XD