大塚製薬
In 1988, player Ishii also became an assistant coach at Otsuka Pharmaceutical. In 1993, he was promoted to manager. In 1997, he moved to Consadole Sapporo and became an assistant coach. In October 1998, manager Hugo Fernandez was sacked and Ishii was promoted to manager. In 2003, he moved to Vegalta Sendai. In September, he managed as caretaker.