ANSWER: When Tonga was once connected to Samoa, the Matai in Tonga wore a Pe'a similar to the Samoan Pe'a. The Tonga Pe'a is still admired by many Tongan Traditionalists, however over the generations, Tongans have begun to wear a Tapa Cloth type of design as a Tattoo on the right or left arms mixed with a National Flag in the center. Even the Tapa Cloth designs that some Rugby Tongans use as Tattoo today (popular one being the Wind motif ) are also the same designs on Traditional Samoan Tapa cloth, its just that the Samoan Wind Motif has never been used as a tattoo before. The authentic Tongan Tattoo is the Tongan Pe'a with a double pronged very attractive looking Tiger-like bar at the top. It stops before the knee unlike the Samoan Pe'a which is longer and a bit past the knee. There have been some Tongans today who have undergone this painful but beautiful Tatatau process.
"Maori too.. have a similar Leg Tattoo witch stops before the knee, but the design is very different. Maori are known for their facial designs, but their leg tattoo is also traditional".
This traditional Tatatau (Tattoo) in Tonga was luckily well documented before the practice became politically discontinued. It was lucky that there was someone with the talent enough to draw it in such detail, and lucky that the person was educated enough to know it was not the traditional Samoan Pe'a.
Traditional Tongan Tattoo