I'm a native English speaker and I'm sorry to say that I think some of the suggested corrections above are wrong, or at least sound a little strange. Here are my suggestions:
<strike>
Recent my worry...</strike> My recent worry...
The Japanese Meteorological Agency said
another tsunami will be sure to come to Japan again within a month. They said the height of tsunami will be 10 meters in Sendai. That is almost same the height <strike>of </strike>
as last time. But we will suffer
more heavy damage <strike>more </strike>from
a second tsunami<strike> . B </strike>
because coastal towns don't have barriers because of the last tsunami. Now, each coastal town's people and
the Japan Self Defence Forces are <strike>do </strike>
doing their best [to revive - I don't understand "to revive". Maybe "doing their best to restore the defences"? Or you could just say "are doing their best.".] But <strike>I</strike>
if the <strike>thing</strike>
prediction <strike>become </strike>
becomes reality, that will be meaningless. <strike>I don't hope it. </strike>
I hope it doesn't.
[I desire to smile in all Japan<em> I don't understand this</em>]. All Japanese are thankful to people around the world. Thank you very very much.
I also hope this doesn't become reality.