This study analyzed yen-dollar exchange market price fluctuations and the shape of the order book observed in the foreign exchange (FX) market at the time of intervention by the Japanese government. Using the comprehensive data of the order book during the yen-sold (dollar-bought) intervention in 2011 and yen-bought (dollar-sold) intervention in 2022, we found that methods of intervention used by the Japanese government in 2011 and 2022 were quite different in the sense of strategy.Intervention in 2011 involved a strategy placing a large number of buy orders on a price absorbing a large number of market orders, while intervention in 2022 involved a strategy placing a large number of sell limit orders at a price lower than the best bid price. Next, simulations of market price movements during FX interventions were conducted by generalizing a model known as the spread dealer model.We introduced the concept of volume into this model and further modified and formulated the effects of stop-loss and take-profit, as well as modified the intervention effects, to simulate market price fluctuations during these interventions.We decomposed the time series into upward and downward trends, assuming that dealers have certain strategic parameters under each trend. Parameter search was performed by randomly selecting parameters within the search space.By searching for parameters that minimize the error function between the real time series and the simulated price time series, and optimizing dealer parameters under each trend, we obtained parameters for the dealer model that could replicate time series closer to real price fluctuation.The generalized dealer model developed in this study has the potential to be utilized in the future for estimating the number of interventions conducted and assessing the efficiency of interventions.