Why did Tonga buy spitfire?

The only connection I can think of is the WW2 Presentation aircraft. During WW2 it was the custom for towns, businesses and even people to donate money to the RAF to have an aircraft carry their name or family crest. Almost 1,300 Spitfires flew with such names, all as part of the Royal Air Force. Two of them were Prince Tungi Tonga 1 and Prince Tungi Tonga 2.

google -Spitfire,prince tungi tonga.