When you apply for ICS (I think not limit to our school anyways), you want to differentiate yourself from the rest. Tell a compelling yet interesting story. Ask yourself why ICS, Why Japan, how has your past experience, either in life or work, helped you come to such conculsion, and how ICS can help you in acheiving what you want in the future. I think these are the main points you need to consider when you apply. Like other MBA schools, ICS likes diversity, it is a big plus if you have a international background. But if not, prove to them that you work well with other races, because during your MBA, you would have to work with people from different countries, you need to tell them that you can handle that. I think you can submit more reference letter as they say you can submit more information about yourself because they want to get to know you better. Good luck! BTW, I had to write in English because I am at work =)
Depending your luck, outcome can be quite different. This year, Chinese students got placed both in Japan and outside of Japan for IBD and consulting etc etc, so it is not that bad.