vocadb says dec 13, this wiki does too and it says akeko came with jan 2012 edition of winodws 100, utau wiki 2.0 says jan 13 2012 though and taht she came with the starter pack, as does utua wikia, which also says akeko came with jan 2012 edition and later in the page dec 2011 and starter pack,. the wikia seems to confuse akeko with mizuno, a different windows 100 utau, for some reason though, linking to her nicocnicopedia page and refering to mizuno in the body of the article,, this is the niconicopedia article that should be linked, which also says akeko was available in the dec 2011 edition and the starter pack (which came out on 23 jan 2012 btw)
as such i am moving akeko to dec 13