If you pray, you probably think some sort of god hears your prayers, right?
Where was this god when Japan was hit with the earthquake and tsunami?
The best case scenario would have to be that this god did not cause the disaster but simply allowed it to happen, knowing how many would suffer.
Does it make any sense that such a god would be interested in your prayers now?
If you are praying for the Japanese people, please recognize that you are doing this only to comfort or distract yourself. It is for you, not for them. It does not do them any good.
If you really want to do some good for the people of Japan, donate to a relief agency.