Long considered a smoker’s paradise, Japan passed its strictest regulations yet on indoor smoking in 2018 with revisions to the Health Promotion Law and a new ordinance in Tokyo. Timed for the Tokyo Olympics, both reforms made smoking regulations stronger and more legalistic despite reflecting distinctive policy paradigms in their particulars. The national regulations curtailed smoking in many public spaces but accommodated smoking in small restaurants and bars. Tokyo’s stronger restrictions emphasized public health protection by exempting only eateries with no employees. I argue that fully understanding these contemporaneous reforms requires analyzing insider activists: state actors who participated in the tobacco control movement or had sustained interaction with it during earlier reform waves. Case studies drawing on interviews and movement and government documents illustrate the mechanisms insider activists can access because they straddle multiple fields. This article contributes to scholarship about ideas, policy entrepreneurship, and the blurry line between insiders and outsiders in policymaking.