Arigato in Japanese and obrigado in Portuguese. Are these words related? I know the Portuguese once

Arigato in Japanese and obrigado in Portuguese. Are these words related? I know the Portuguese once had a strong influence on Japan, including the use of loan words, for example tempura and igirisu (Enlish).

Bjorn Haglund, London England

• It's purely a coincidence with no etymological foundation. Arigato is merely the shortened form of arigato gozaimasu.

  David Lane, Venice, US

• Yes, they are related.. http://www.youtube.com/watch?v=shRYGtYwIuM&feature=player_embedded :)

  Micaela, Lisbon Portugal

• No, these words have no relation. ARIGATO (arigato gozaimasu) had existed in Japanese even before Portuguese reached Japan in 1542.

  Vandan, Ghaziabad India

• No, this is a very well-spread rumour, but nothing more. There is no evidence that the words are somehow connected. Moreover the word arigatougozaimasu existed before the Portuguese ever arrived in Japan. And I personally feel it's quite unlikely that Portuguese had such a strong impact on a matter (politeness) that was already fully developed in Japan. As for what concerns the use of "obrigato" instead of a correspondent to "gracias" and "grazie", "obbligato" in Italian was used as late as the end of the 19th century, was still written currently before WWI and is still seen in highly styled letters nowadays. And I doubt the Italians have had such a great influence from Japan.

  Kiknos, Italy