Question: fun things to do on a rainy day with a friend?
Answer: Go to a museum or an art gallery. Bet you haven't seen all of them, have you? ... 
Visit a cave. ... 
Go on a spontaneous road trip or catch a train. ... 
Plan a trip. ... 
Create a road trip playlist. ... 
Unwind at a hot spring or spa. ... 
Find the best brunch spot in town. ... 
Bake some goodies.