Japanese Missionary Converts Japanese Family in South America
MYTH: A Japanese speaking missionary is called to serve a Spanish speaking mission but ends up converting a Japanese family.
This is a common missionary myth that can be found in numerous forms. As this particular story goes, a missionary of Japanese ancestry was called to serve in Colombia, speaking Spanish, though he desperately wanted to go to Japan. At some point in his mission he meets a Japanese family whom he is able to teach in his native language. In this particular variation he discovers the family has a Japanese Book of Mormon given to them by his father many years earlier.
This is another one of those inspiration/motivational stories that lacks sufficient evidence or verification (although according to http://www.shields-research.org, this story bears vague resemblance to the experiences of Masakazu Watabe, a missionary of Japanese heritage who served a mission in Brazil.)
I have personally experienced a variant of this story in a ward growing up. The story was of a sister missionary who spoke fluent French (having studied it for four years in school and who had lived for a short while in France.) But she was called to serve a mission in Spain, Spanish speaking. She struggled with the language her whole mission, never really getting the hang of it. However, before the end of her mission she tracted into a French speaking family and was able to teach them. Although I grew up hearing this story, I was never able to confirm specifically who this missionary was.
It is absolutely possible that such stories really happened, but without definitive evidence I have to say that this genre of missionary story is nothing more than motivational myth.