Surgical correction of the subvalvular apparatus to reduce tethering, along with mitral annuloplasty, has recently been highlighted in the treatment of functional mitral regurgitation. However, because of anatomical differences in the subvalvular apparatus between cases of progressive cardiomyopathy, a uniform procedure to reduce tethering has not been established. We report a case-specific reconstructive method consisting of procedures mainly on papillary muscles for a rare case of dilated-phase hypertrophic cardiomyopathy with moderately severe mitral regurgitation.