It's not from an Anime, rather from a voice synthesizer software by Yamaha called Vocaloid. Hatsune Miku was created in 2007 and is one of the most popular Vocaloid characters ever. Even from those who even don't watch anime or use Vocaloid knows this character, which actually confuses people into thinking that Miku is from an Anime.
Not an anime but an adult manhwa called Circles (or Dangori for the Korean title) she is one of the few prominent characters to not be "involved" in adult stuff, she is such a precious creature istg.
Origin is a game not an anime, though, and I actually Photoshopped the game assets to create this wink that ISN'T a real expression in the game itself. Also because the asset was practically a "tachie" (立ち絵) sprite, I added a background to play nice with services which don't transparent avatars.
......Priconne does have anime adaptations, though.