It's a Japanese surname. It is also a rare surname in Japanese surnames.

A probe into the origin of Chiba surname

The name Chiba is the last descendant of Emperor Kanmu Haowenliu. At the end of heian period, he moved to Chiba Village, which is equivalent to Chiba City, Chiba Prefecture, and began to use Chiba's surname.

The descendants of the Chiba family are mainly distributed in northeastern Japan. For example, Sendai in Miyagi (the descendant of Data Masamune, the guardian of Chiba family) has the most, and most of them are prominent families. It is a rare surname in Japan, which often appears in TV dramas, but rarely in reality. It is one of the better Japanese surnames.