Large-scale events bring tourists to host cities and increase the density of people circulating therein. Pokémon Go Safari Zone events have been hugely successful at attracting tourists to cities around the world. For example, in one five-day Pokémon event in Tainan, Taiwan in 2018, the daily log-in count was 250,000 per day on average, generating an estimated US$50 million in revenue for the city. In order to better understand the impacts of Pokémon and other similar events on bikeshare systems, this study examined changes in station-based bikeshare trips before and during one case study event. We divided bikeshare trips into event-related (i.e., treatment) and event-unrelated (i.e., control) groups based on whether the trips originated from rental stations near 30 scenic event-related locations. We also evaluated the event’s impact on the number of trips and trip durations for different smartcard users. A difference-in-difference method was used for the analysis. The results show that this event increased bikeshare trips by 27% for trips starting from event-related rental stations. The number of riders making payment by EasyCard (a smartcard first used by Taipei Mass Rapid Transit) also increased. However, there was no significant change in the duration of bicycle rentals between different smartcard types. Understanding how this event and the associated bikeshare systems are interrelated will be helpful for city administrators seeking to provide adequate services for such events in the future.