 Domestic arrangements proved strained even before Léonie belatedly learned of the existence of Takeda Matsuko, around the time of Matsuko's second pregnancy by Noguchi.Léonie separated from Noguchi in 1909, taking Isamu, and living in a series of residences in Ōmori, Yokohama and Chigasaki.In 1912 as a result of a relationship with a man whose identity remains mysterious (Isamu Noguchi biographer Masayo Duus speculates that he was one of Léonie's students) she gave birth to a daughter, Ailes Gilmour.