高田藩
Mitsumichi was married to his cousin, Kunihime (1636-1671), the daughter of Matsudaira Mitsunaga, "daimyō" of Takada Domain. Kunihime was a noted "waka" poet, and had been sought after in marriage by the "kuge" nobles of Kyoto; however, there was political opposition by the shogunate, which was leery of possible collusion between the two powerful Matsudaira domains. Her marriage to Mitsumichi was delayed until 1655, when both were already 19 years old - considerably late for the marriage of the legitimate wife of a "daimyō". Kunihime had two daughters (both of whom died in infancy), and although relations with Mitsumichi were apparently good, there was tremendous pressure to produce a male heir. Mitsumichi took a concubine, Lady Osan, by whom he had a son (Matsudaira Naokata) and a daughter. This created a rift between Fukui and Takada, as his father-in-law Matsudaira Mitsunaga insisted that any heir should be by the legitimate wife (i.e. his daughter). Unable to bear the pressure and uncertain that she would be able to have more children at the age of 35, Kunihime committed suicide in 1671. The shogunate bowed to Matsudaira Mitsunaga's request, and declared that Matsudaira Naokata would not be allowed to succeed to Fukui Domain and would be exiled to Ōno instead.