Kamisama no Volley

Analyst...a "team mastermind" who analyzes the opposing team and instructs the coach on strategy from off the bench. Soichi Azuki is an analyst for the Nimura Kasei Gunmen's, a professional volleyball team. He is promised the position of All-Japan men's volleyball coach on one condition. That was to make the boys' volleyball club of a private junior high school, which had always been eliminated in the first round of regional qualifying, win the national championship!

(Source: Houbunsha, translated)