Vocaloid: Tokyo Cyber Detectives

I only got a few more in my system, I think.

In this one, in addition to the well known Crypton vocaloids (Miku, Rin/Len, and Megurine Luka) are the two most well-known from Internet Co, Gakupo (purple) and Gumi (green) as well as IA (light pink). I'm not sure who made IA.

Tokyo Cyber Detectives: [link]

All the vocaloids on the board can attack the king. Can you guess which pieces they are?
(hint: Luka and Gumi are on diagonals, but, y'know, composition posing)