In June 1937, Abbe enlisted in the Imperial Japanese Army, and was subsequently posted to a garrison in Manchuria. He served there for four years, during which time he was unable to continue training in judo but was able to practise kendo. While abroad, he began formulating his Kyushindo philosophy. His tour of duty ended in 1941, and he returned to Kyoto, where he met and married his wife Keiko. Abbe did not remain a civilian for long, however, since Japan entered World War II near the end of that year.