Her official profile says, "She is strong-minded and tsundere; a charming mysterious girl, who is innocent and expressive. She's naive, but usually pretends to know everything." If Lapis can be seen as "light", then Merli would be seen as "dark".
Her race's concept, fairies, is that 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!"
A free iOS and Android app was produced for Merli, called " Good Night Merli " (おやすみメルリ). Much like the one for Lapis, it helps you fall asleep and comes with an alarm.
A second app was released, called "ラピスと魔法のメロディ", which acts as a sequel to "Lapis and the Wonder labyrinth" (ラピスと不思議なラビリンス). While Merli makes a brief appearance in the first one, she appears to make a more prominent appearance in the sequel.