Ghibli is Japan’s Disney and known to every Japanese child. The museum itself was designed by Studio Ghibli’s director, Hayao Miyazaki, and based on the storyboards used to create the films, the most famous of which (outside of Japan, at least) is Spirited Away (2001). The museum includes a cafe, children’s play area, and gift shop.
Note that tickets can only be purchased in advance via authorized travel agents and LAWSON convenience store chain. See the official website for more details. Tickets are released for entrance up to 3 months in advance.