 On the lookout for inspiration on "chanbara" action, Osawa suggested a visit to Toei Kyoto Studio Park, a film studio theme park.There, Osawa, Koizumi and Ikeda entered a playhouse where several ninjas and a main samurai were staging a show.Koizumi observed how only one of the ninjas would attack the main samurai at a time while the others remained in a waiting pattern, which proved to be the solution to designing battles with multiple opponents.