One of the most significant recent technology developments was the commercialization of perpendicular magnetic recording (PMR). Starting in 2005, the adoption of PMR facilitated a tenfold increase of data capacity in hard disk drives (HDDs). HDD capacities of up to 10 TB are the norm today. Researchers at Tohoku University made key contributions in the invention of PMR as well as in the understanding of the physics of PMR and requirements of heads and media. This oral history records the contributions of Professor Yoshihisa Nakamura and Hiroaki Muraoka to the success of PMR.