After the secession from the Imperial Family, he declared himself Mr. Yamashina, however, he was repeatedly hospitalized and passed away in a hospital in Fujisawa City, Kanagawa Prefecture in August, 1987.
皇籍離脱後は山階氏を名乗るが、その後も入退院を繰り返し、昭和62年8月に藤沢の病院で逝去した。