Natsume's Book of Friends Vol. 22 (manga)

Natsume and his friends are visiting an old inn to see a yokai exhibition, but a sudden storm extends their visit into an overnight stay. All should be well, since the inn has a charmed door curtain that welcomes good spirits and keeps out evil. But tonight of all nights, they forget to put it out! Can Natsume and his friends protect the inn without endangering the friendly local yokai?!