A contest was held to determine the name their second character known under the development name of "Project Second". i-Style noted that the chosen name did not have to have a surname at all and surname-less names would be accepted. "Merli" was chosen out of the list of suggested candidates by fans and became her official name.
Merli (Meruri) is named after Merlinite (メルリナイト / Merurinaito), a type of stone known for its dual light and dark appearance. The stone itself being named after Merlin.
Merli is identifiable by 3 distinct traits to her over Lapis in her official bio;
She is strong-minded and tsundere; a charming mysterious girl, who is innocent and expressive.
If Lapis is "light", Merli is "Darkness".
Though she is Lapis' older sister, she is also a rival to her, making them the first protagonist and antagonist of Vocaloid.
As she is the same race as Lapis she shares the same concept. She is also from a fairy race, they are special people who can convert “songs” into “power”, and can only be seen by a subset of the human population. Merli's power draws away the energy of living things; the opposite of Lapis' power.
DanierukunP's 38th work and and first work with Merli. Merli sings of light and dark, and how she cries for the war between the two.
"I just uploaded a song yesterday and I wasn't planning on doing another one for a week or so, but as soon as I heard this awesome track with the newly released Vocaloid 3, Merli, I just couldn't resist uploading it for everyone to hear!"