We very happily stumbled across the International Manga Museum in Kyoto and stopped for lunch and a good look around.
Both of us are reasonably interested in 'whimsical pictures' as Manga translates, and found it fun to spend an hour or two searching among the work of great Manga stars like Osamu Tezuka (creator of Astro Boy and the beautifully illustrated story of Buddha) and the Year 24 Group (a group of female Manga Artists).
They also had a fantastic exhibition of international Manga, including a great collection of DC Comic's Superman series:
I think Ophelia probably had the most fun in the children's library. They had a fabulous international collection of kids comics.