Medical devices are expected to play more important roles in improving prevention, diagnosis, and treatment of, for example, cardiovascular diseases, the leading causes of death and disabilities in aging population. Percutaneous coronary intervention (PCI) has been one of the fastest growing categories in medical devices to be challenged by clinical trials to test improvement in quality of life or survival of patients with ischemic heart disease. Since clinical evaluations of PCI have evolved into healthy competition among PCI, bypass surgery, and pharmacotherapy, all stakeholders including industry, regulatory authority, as well as medical practitioner equally benefit from constant improvements, and, ultimately, patients are winners. Pharmaceutical Affairs Law of Japan (PAL) has constantly been amended in parallel to global regulatory guidance documents. PAL categorizes diagnostic and therapeutic medical devices into classes according to risks. It integrates frameworks like the Essential Principles so that reviewers and/or conformity assessment bodies can take harmonized approach to facilitate approval processes. Discussions about so-called “Device Lag”, some argues US/EU approved devices should immediately be approved in Japan while others argue innovative Japanese manufactures should find more market outside of Japan, reminds us all that regulatory harmonization should be mutually beneficial. The Global Harmonization Task Force (GHTF) has been conceived in an effort to achieve greater uniformity between national medical device regulatory systems. The Harmonization by Doing (HBD) is a pragmatic effort to conduct US-Japan international clinical investigations and FDA-PMDA/MHLW joint reviews. Activities like GHTF and HBD could complement each other to effectively harmonizing regulatory processes while leaning from experiences.