However, the lunacy of his brother Tadayuki who had inherited the main family heritage and Furukawa Domain led to forfeiture of his domain in November 1693; subsequently Nobumichi was appointed as heir of Matsudaira (Sakurai) family and was transferred to Niwase Domain of Bicchu Domain with increase of rice yield by 20,000 koku, resulting in the closure of Okidome Domain.
しかし元禄6年（1693年）11月に本家の家督と古河藩を継いでいた兄の忠之が発狂したために改易されると、信通は松平（桜井）家の家督を継ぐこととなり、2万石加増の上で備中国庭瀬藩に移封され、興留藩は廃藩となったのである。