What makes you think Kaori was on that "sect"? Toshi knew Masaya's music because he found a CD at a Music Store, listened to it and got hooked, that was about a year BEFORE he married Kaori (he did it on February 17, 1997).
Source? Toshi Official OHP, Iyashi no Concert one, in the History section. Also, some of his books say it as well, like Aoi Hoshi no Tabibito Photobook which I own, released on 1996 after he got interested in Masaya, the pictures took place in Yakushima Island, Masaya used to frequent that place.