Complex sentence: On May 21, he started the pro career as 浜田剛 which is his real name, in Tokyo, and his ring name was changed into 浜田剛史 which has the same pronunciation, in 1983.
Split into simpler sentences: On May 21, he started the pro career as 浜田剛 which is his real name, in Tokyo. His ring name was changed into 浜田剛史 which has the same pronunciation as the real name, in 1983.