66 Roro is an original character created by Manbou no Ane. It is viewed as one of the many concept appearances for the VOCALOID2 product VY2, though it should be noted that the current VY series have no official avatars.
According to the design concept, he is an android with pale skin, yellow or blue eyes, and pink hair. He wears a beanie and a hoodie with a heart emblem along with either a striped necktie or a choker, and has speakers on his hands which resemble a pair of black gloves. He carries around a pink katana with an equally pink sheath. Drawn with more human traits, the hand-speakers go away. His expression never changes, only sporting a pair of jitome.
The character later appears as a side character in Manbou no Ane's GanGan Online manga Ukare Bakemono no Hogaraka na Hatan, and became officially integrated within that series' cast. There, he's given the name of Rokugou.