Simplify the following text for a Grade 6 native English-speaking person.
Original: Uesugi Harunori was a Japanese daimyo , the 9th head of the Yonezawa domain ( today 's Yonezawa and Okitama region ) , and a descendant of Fujiwara no Yoshikado .
Simplified: He was the 9th leader of the Yonezawa domain . This domain the area that today is the Yonezawa and Okitama region .