After the retirement, Tsunami started coaching career at Verdy Kawasaki (later "Tokyo Verdy") in 1999. He mainly served as manager for the youth team. In 2005, he moved to Vegalta Sendai and became a top team manager. In 2006, he returned to Verdy and became an assistant coach for top team under manager Ruy Ramos. In 2007, he moved to Cerezo Osaka and became a manager. However the club results were sluggish and he was sacked in May. In 2008, he signed with Yokohama FC and managed the club in 1 season.