In 1941 he was drafted into the army under the 6th Field Heavy Artillery Reserve Company stationed in China.

As an educated non-commissioned officer he was assigned to senbu operations, presenting kamishibai to Chinese civilians.

Post-war alongside other veterans Yanase made a living collecting garbage.

Hearing that his co-worker Nobu Komatsu was quitting and relocating to Tokyo, Yanase did the same.

The day after his death, an obituary in the October 16, 2013 edition of the Tokyo Shimbun reported that he was "a dandy Christian with a strong faith.