I have a chirashi of the tour in my collection. A chirashi is basically a flyer or handbill, about the size of a standard piece of A4 paper. Japanese chirashi since the 1960s have been pretty high quality and there is an organized hobby of chirashi collectors out there. Mostly these focus on movie chirashi, which feature amazing artwork advertising films made only for their Japan release (I have a lot of these, they are awesome), but they also make them for other events like concerts (I have a pretty good Rolling Stones one from a 1970s tour they did) and exhibition baseball games like this!
This one is pretty cool, prominently featuring Hall of Famer George Brett front and centre. It isn't actually a chirashi for the whole Kansas City tour, but rather from the leg of the tour which brought the Royals through the Kansai area. The back advertises games they played against a mixed Giants/Braves squad at Nishinomiya Stadium, an all Japan all star team at Koshien Stadium, and a mixed Hawks/Buffaloes/Giants team at Osaka Stadium.
Kind of a neat piece of US-Japan baseball history!