I am just thinking that a girl under 25 might be better.
the second link I you gave seems to be not true since the photos of the website are from a Chinese actress.
anyway, in London it's really hard to find a really pretty Korean girl like the ones in stellar. I once happened to ask a girl about it, and she told me that "no pure Japanese in London, I would say, and there is few Korean girls but you might prepare 500 to meet them."
just can't imagine
Is all to do with economics.
There are quite a few Japanese, korean girls in London but these 20's / early 30's girls who either live in UK and do this part time or those that travel to UK for vacation and do this erotic massage/escorting work for a few months. Obviously they are traveling from developed countries so they can equally make good money back home or the money they need is high to support living back in their home country - cost of living is high.
I usually only go for a body2body or nuru and only occasionally an escort or if she offered me something extra in the booking and was in the mood.
Their prices will typically be more than other Asian girls from say China (although some Chinese girls from Shanghai coming to UK and other parts of China are going up as costs rising in some cities there too), Taiwan, Thai, Filipino, HK etc but not too much more.
I would say a Japanese/Korean (real) in London:
Body2body / nuru - ranges from £100-£150 for 1 hr
Escort ranges from £150 to £250 for 1 hr.
That is why is far easier to find girls cheaper in London from poor countries (but I am just not usually attracted to some of those nation girls - exception are Russian's who I love too) - Eastern Europe / India / Africa etc.. as the money is much better for when they are saving to send back home as cost of real estate/ living is so cheap in their home nations.