Will it do any good to pray to a God the Japanese people don't believe in?

Virtually all the Japanese are not believers in any single religion. They are, rather, syncretic believers in a mixture of Shintoism and Buddhism; itself a syncretism of Theravada Buddhism, which is prevalent in India and much of Southeast Asia; the more personal Mahayana Buddhism of China, Tibet, Vietnam, Korea and Japan; and Vajrayana Buddhism. Japan has full religious freedom and there are minor numbers practicing Christianity, Islam and Sikhism. But surveys find that 84 to 96% of the population subscribes loosely to their unique mixture of Shintoism and Buddhism. Japanese joke that they are Shinto for weddings and Zen for funerals.

So given that very few people in Japan even believe there is a Abrahamic God of any name, does it do good for American Christians to pray for the people of Japan in their time of need?