Couple hours between Kyoto and Osaka

[Columbine]

If you know how to get to Kyoto National Museum, Sanjusangendo is within spitting distance of it, and that's got a (smallish but full and interesting) indoor museum, which is well worth a visit. That could kill about an hour. And double check on the National Museum. Not to be funny, but it's split into two halls, and one shuts to change the feature exhibit over, whilst the permanent collection might just still be open. Or you could hop on the Keihan line at Shichijo (about 5 mins walk from Kyoto National Museum, on the river) and go up two-three stops to Sanjo; there's a bunch of art museums up there. Not sure which ones, there's the modern art and the municipal one's there too maybe...I think the trad. craft museum is knocking about up that way as well, alongside the heian shrine. You might want to see if you can't drive up that way though if it's raining, it's a bit more of a walk from the station.