厚木海軍飛行場
In December 1944, Muto was posted to the Japanese Home Islands to join Captain Minoru Genda in his 343rd "Kōkūtai" formed to defend against Boeing B-29 Superfortress attacks. Muto has also been identified as a tactics instructor with the Yokosuka Air Group, based at Naval Air Facility Atsugi in early 1945. There, Muto flew a powerful Kawanishi N1K-J "Shiden", a type codenamed "George" by the Americans. At that time, he and his wife Kiyoko were expecting a child.