Why was it surprising that so many Japanese Americans volunteered to fight for the U.S. armed forces? It is surprising that the U.S. was able to keep a record when so many Japanese Americans were still in camps. Japanese Americans needed to spend five years in training before they were allowed to join the armed forces. Many Japanese Americans fought to serve and protect the U.S. even though they were being mistreated by the U.S. Japanese Americans were busy working at the camps so it is surprising that they found the time to join the armed forces.