I remember being really into this subculture a few years back when it was REALLY big. There are many different variations of Lolita (the most common being Gothic Lolita and Sweet Lolita, other variations include visual kei, a j-rock interpretation, and so on...)
Yes, it definitely is an influence from 18th century France and from the victorian/edwardian era of Europe. But this is yet another cycle of Japonisme (when Japanese aesthetic/culture became HUGE in europe around mid-to-late 1800s), and ever since then there has always been a strong connection between aesthetics from Japan-to-Europe.
When it comes to the sexual undertones, the lolita look can easily be pushed and molded into different directions. Some more playful/whimsical, some more girlish, some more sexual, some more menacing/obscure.
I remember checking out Lagerfeld's Chanel-TOKYO pre-fall collection in 2005 (for some reason, it's ridiculously difficult to find photos of). Very fitting, blurred the line between contemporary French and Japanese fashion.