Seiji Yamakawa (山川 征二 Yamakawa Seiji) is a Japanese retired professional wrestler, better known by his ring name Ryuji Yamakawa (山川 竜司 Yamakawa Ryūji). He is best known for his time with Big Japan Pro Wrestling (BJW), where he spent the majority of his career between 1995 and 2012 as a deathmatch wrestler. He was one of the top wrestlers and an over main eventer of the company, winning the Deathmatch Heavyweight Championship two times and the Tag Team Championship seven times.