Emperor Kōkaku
was Japanese royalty. He was the 20th/23rd prince Fushimi-no-miya and the eldest son of Prince Fushimi Sadayuki (1776–1841) and his concubine Seiko, which made him an 11th cousin of Emperor Sakuramachi. Despite being merely a distant cousin to the emperors, he was adopted by Emperor Kōkaku as a in 1817, which made him a Shinnō, or prince, just like an emperor's natural-born son.