In 1898 Gauntlett married Tsune Yamada (the older sister of composer Kosaku Yamada). When they married,marriages between Japanese and foreigners were not recognised by the Japanese government. On the advice of a Japanese lawyer, all record of Tsune's Japanese nationality had to be expunged and Edward had to petition Queen Victoria to 'adopt' Tsune as a daughter of the British Empire. The petition was successful, and a letter from Queen Victoria arrived in due course. Later, the Japanese government introduce legislation that would legalise marriages between Japanese and foreigners, so Tsune recovered her Japanese identity. It is said that theirs was the first officially registered marriage between a Japanese and a foreign citizen. [2] He and his wife had six children. Their eldest son, John Owen Gauntlett, taught English at Aoyama Gakuin University and was also a flautist. J. O. Gauntlett also gave a set of lectures on teaching English as a foreign language at Nanzan University in Tokyo, that were edited by James A. Noonan and then published as a book by MacMillan Press.[3]