>>49435908
>and back into the house
And one leading outside.
I'm not sure what the other rooms would be used for, but I'd assume:
resting place for some of the animals (although the senkai would already be very safe for them as is, and the weather is perfect)
place to wash clothes
bathroom (I assume this is likely on the 1st floor, but it's not impossible that Kasen has plumbing to let it be on the 2nd. I found an instance of Reimu having an actual running water tap in the Hakurei Shrine after all.)
Maybe different types of storage rooms?
Guest room?
There's a lot of possibilities.