Dyna Chair was a Japanese talent agency based in Dotonbori, Osaka. The company was founded by Mirei Park shortly after her divorce from Goro Majima in 1992, and she and Naoki Katsuya created a fictitious rivalry between Park's Dyna Chair and Katsuya's Osaka Talent to generate buzz. In 2012, after the T-Set duo left for Osaka Talent, Park cultivated Haruka Sawamura as her star idol, and Sawamura defeated T-Set in the Princess League. However, Park was murdered by her disgruntled employee Kan Ogita and Sawamura's manager Hiroshi Horie injured in a similar incident of yakuza-related violence, and Misa Yamaura took over as Haruka's manager until she retired following a performance with Dream Line at the Tokyo Dome.