These cards were included as prizes in Calbee snack foods during the Showa 50s (late 1970s to early 1980s). Fujiko. Shogakukan. TV Asahi The content is like a children's encyclopedia. Easy to understand with illustrations and explanations. There are three series: Nande mo Hyakka (Anything Encyclopedia), Terebi Gekijo (TV Theater), and Dora-Happer Quiz (Doraemon + Ninja Hattori-kun + Perman). They are about 50 years old, but are in excellent condition with no discoloration, and the corners of the cards are so sharp they look like they could cut you. Thank you for viewing.