Rows of wooden mortuary tablets inscribed with names line an altar at a Buddhist temple in Tokyo — silent testimony to Vietnamese people who died after coming to Japan to work or study.

"Whenever I am contacted about a death, I can speak only two words: 'Why?' and 'Again?'" said Thich Tam Tri, a Vietnamese Buddhist nun who has been counseling migrants from her home country after arriving almost two decades ago.

"These young people ... were living in great poverty in remote rural areas and their parents were suffering hardship," she said after offering incense and prayers at the altar of Nisshinkutsu Temple in Minato Ward.