Monster Musume, other known as Everyday Life with Monster Girls, is a mature harem genre anime and manga series. Basically, the protagonist ends up hosting a bunch of half human, half animal/mystical creature ladies in his house in a NSFW manner.
One of the characters is Mero the mermaid. Mero wears “gothic lolita.” Clearly this isn’t lolita, but the inspiration is there as you can see with the headdress and the stereotypical anime black and white combo.
I ended watching all 12 episodes of the tv anime looking for this scene, but a friend pointed out that it’s actually in one of the animated short specials. In Monster Musume Almost Daily Life Special Issue 5, Mero is seen shopping for clothes on her tablet.
Those two pieces are actually real Atelier Boz dresses! The first one is Boz’s Zeno Dean Jacket OP and the second one is Ralfe OP.
It’s one of the last places I’d ever expect to find Boz, but it’s a pleasant surprise. The show is alright though and the mermaid girl did end up being my favorite. There’s nothing else lolita-related in the show, so I wouldn’t recommend Monster Musume if you’re looking for a lolita anime.