Answer
Yes, Takeshi Okada has indeed coached in the J League. His coaching career in the J League spans several years, where he managed various clubs, including Consadole Sapporo, Yokohama F. Marinos, and Cerezo Osaka. Throughout his tenure, Okada demonstrated his tactical prowess and leadership skills, helping his teams achieve notable results and shaping the careers of numerous players who went on to make significant contributions to Japanese football.