Koki Yamaguchi (山口 航輝, Yamaguchi Kōki; born August 8, 2000) is a professional Japanese baseball player. Selected in the fourth round of the 2018 NPB Draft from Meioh High School in Akita Prefecture, he plays outfield and first base for the Chiba Lotte Marines.
Source: “Koki Yamaguchi”, English Wikipedia (CC BY-SA 4.0), excerpt