I,m managing the site of kaigaisokin.seesaa.net/.
If you or your friend can't understand Japanese well,
I think Elldridge Lynch is the easyest way for you.(Chose English!)
You have to remit your money to Elldridge Lynch from a Japanese bank counter, but you can remit your money to U.K. from your p.c. in English after then, and foreign money exchange fees are cheaper than other banks.
the custamer representatives of Elldridge Lynch can understand English well.
If you or your friend can understand japanese well, you can chose the way from Citibank Japan (e-saving account).
The spread between Middle rate and T.T.S of British pond and yen is smaller than other banks.
(Citibank 1.0yen, Lloyds 2.5yen others 4.0yen for middle rate of about 150yen)
Over about 2,000,000yen, you can chose other ways.
One way is Gaika-Ukewatashi, but I think difficult even for ordinary Japanese.
Be carefull for the name and swift code of the bank in U.K.
kazuboy