Samurai

Samurai were members of the aristocratic military in the feudal government of mediæval Japan.

In Japan
Katsura Sato was originally a samurai warrior from the 17th century. (COMIC: The Road to Hell, The Glorious Dead)

While the Vondrax were trying to recover one of their orbs in Japan, they took the form of samurai warriors to blend in. (PROSE: Trace Memory)

A Samurai warrior was brought forward to the early 21st century by the Rift Manipulator, where he began to terrorise travellers on the Tokyo subway system. (TV: End of Days)

Other references
One of the many guises that Chancelor Goth used whilst battling the Fourth Doctor within the Matrix was a samurai warrior's armour. (TV: The Deadly Assassin)

The Origami Warriors of Draconia had the appearance of Samurai Warriors. It could even be argued that the Draconians had a samurai style culture. (AUDIO: Paper Cuts)

The Sea Devils of Elite Group One wore samurai-style armour. (TV: Warriors of the Deep)

Strax once claimed to have a hoard of rabid samurai apes. (COMIC: The Adventures of Strax & the Time Shark)