Matsudaira Katamori
Being an important member of the Serizawa faction, Nishiki was later forced by Yamanami Keisuke and Hijikata Toshizō to commit seppuku(suicide) around October 19 (by the lunar calendar, the 10th day of the ninth month), 1863. Serizawa and the other members of his group were assassinated about a week later by order of Matsudaira Katamori, the "daimyō" of the Aizu clan.