After graduating from the University of Tsukuba, he joined Japan Soccer League club Mazda (later Sanfrecce Hiroshima) in 1984.
After retirement, Mochizuki started his coaching career at Mazda (later Sanfrecce Hiroshima) in 1988.
In November 1998, he became the goalkeeper coach for the Japan national team under manager Philippe Troussier.
In October 2000, the Japan national team won the Asian Cup.
This biographical article related to a Japanese association football goalkeeper is a stub.