In 1848 he was adopted by Haruyoshi KAWASE, who was Karo (chief retainer), as a son because of his talent and identified himself as 'Hideji,' and given a Chinese character from Munehide HONJO, the lord of domain.
嘉永元年（1848年）才を見込まれて家老職を務めていた河瀬治休の養子となり、藩主本庄宗秀より一字を与えられて「秀治」と名乗る。