According to the account in the Christ Museum next to the tombs, Christ arrived in Japan at the age of 21 and learnt Japanese before returning to Judaea 12 years later to engage in his mission and preach about the "holy land of Japan". The official Shingo history is that Jesus' place on the Cross was "casually" taken by his brother, leaving Christ free to return to Japan. On his return he fell in love with Miyuko, a local girl, and lived happily with his family among the rice fields until dying aged 106.
The Times' article is a bit skimpy on historical details, but a quick Google search of japan christ's tomb brings up a long list of links with more 'information', including one of my personal favorites from Learn the Bible, which calls the entire notion a "blasphemous heresy". Here you'll read about more "false" and "blasphemous" stories of Christ, from the "African Legend" to the "Mormon Myth" to "The Da Vinci Hoax." "Here is the question to ask yourself," the author says. "Which one is true? The answer is clear – they can't all be true. They are all false." Well, I can't argue with logic like that...