Can I apply for a tourist visa for my entire family (my wife and two sons) without them present?

We plan on visiting Beijing the second week of April. Do all four of us need to be present to apply, or can I take all our documents and apply for us all together by myself? Also I am an American citizen but have been living in Japan for twelve years, will I need to pay the 15000 fee for each of us?!?! My sons are nine and five years old.