Are they from an Anime?

Looks to be from something called Moldavite (?) And a few characters also seem to be crossed over from Kao no nai Tsuki

From what I've found ALL of the characters seem to be from an Adult hentai game, Moldavite (wow that título is not good in English sounds like moldy vitamins??)

The girl in the red dress is named Stella Arista and the boy in front of her is Vine Trident.
The girl behind Stella is Annette Vaslois
The really small girl with buns siguiente to Vine is Yung Ming and the girl below her with the frilly purple dress is Dorethea Arusutoromerisu.
The brown haired girl siguiente to her is Caren Mayfield and the green haired girl in naranja above her is Cynthia.
The green haired girl behind her with the strange hat is Evelyn Hayworth, and the little girl with the giant bow is Nina Fromm. Lastly the girl behind all of them is named Mistrel.

Basically I was able to name all of them (courtesy of the anime character data base) so unlike what Cerudays dicho none of them are crossed over from Kao no nai Tsuki.