Mochizuki was born in Otsu on May 18, 1964. After graduating from Osaka University of Commerce, he joined Japan Soccer League club Nippon Kokan (later "NKK SC") in 1987. The club won the 2nd place at 1987/88 Japan Soccer League and the champions at 1987 JSL Cup. In 1992, he moved to J1 League club Urawa Reds. In 1995, he moved to Japan Football League club Kyoto Purple Sanga. In 1995, the club won the 2nd place and was promoted to J1 League. He retired in 1996.