Cigarette prices in Japan are lower than those in most other high-income countries. A more striking fact is that cigarette tax revenues have been kept almost flat at just over two trillion JPY (Japanese yen; 18.2 billion US dollars) over more than three decades, despite steadily declining cigarette sales and seemingly weakening pressure from stakeholders with a vested interest in the tobacco industry. We attempted to examine trends and determinants of cigarette tax increases in Japan. In particular, we hypothesized that the Japanese finance ministry adjusts cigarette taxes to meet a revenue target. Under this hypothesis, we searched for the most plausible amount of the minimum target of tax revenue that corresponds to cigarette tax increases over the past 37 years (1985-2021) using public data on cigarette sales and taxes. The results revealed that two trillion JPY was the minimal revenue target that could plausibly explain the increase in cigarette tax. In addition, the timing and magnitude of cigarette tax increases have been successfully set to maintain stable tax revenues. A key determinant of cigarette tax increases in Japan has been hard revenue targets, rather than public health concerns.