I will be going to Japan through OMF International.
I chose OMF because of its 150 year history in East Asia, it specific and focused training on East Asian culture, language and the Bible, its detailed and thorough preparation of all the missionaries it sends there, the long and successful retention of its missionaries, the large participation of people of Asian descent in its staff and among its missionaries, and its focus on building up the national church, national servants and national leaders (ie in my case the building up of the Japanese church through Japanese Christians and Japanese leadership).
I think you will approve of and want to support the organization as well, the more you learn about it. You can learn more through the links below.
History of OMF International History (PDF)
Purpose and Principles_for_OMF_International (PDF)