Me and Japanese Girls

One of the girls working at Kinokuniya, has this really annoying high pitched cartoony voice that normally just provokes the "I want to slap that girl in the face and tell her to snap out of it, or just keep it up and continue promoting 1950s women's right level". However, she smiled a lot, and when finished packing my groceries she said in English very carefully, "thank you", I replied. She said "have a good evening". I replied and she smiled with her whole face. I had to tell her, you look so happy that you make me happy just looking at you. She replied "ohh, thank you, thank you so very much. Bye bye see you soon".

I guess it was kind of good I did not slap her in the face to start with, but should probably inform her about the risk, just for future reference. Also got me thinking if Japanese girls are very friendly, bubbly, contact seeking in general or is there something happening when combined with a Swedish girl?