Getting Japanese style nails outside of Japan can be really difficult, as not very many places know how to do the sculpting of 3d art, or how to do any of the crazy stuff you want on top of your nails. London is renowned for having nail salons everywhere, majority of the owners being asian. Your friends all go to one, and recommend etc etc .
If you want to have something specific, you need to do your research. Take a picture of the design that you want before going to have your nails worked on, and see if there is a genuine response from the salon. If not, its not the place for you. Many salons offer "Japanese nail art" but can't actually do any. A lot of people only associate "Japanese nail art" with a few 3d flowers (not difficult to learn and do) and some sakura style colourings. Wrong. They clearly haven't seen the Tokyo Nail Expo!
Ive only ever had my nails done in a shop twice, last night being my second time, because I usually just wear false ones from FULLMOON or I make them myself (theres no limits this way). Since coming back from Japan, I had been following Yuma Takahashi and Aina Tanaka's blogs, and I saw this come up on Yuma's not too long ago: