Average mans trip to Gensokyo

An average guy unlike any other is sent to the world of Gensokyo through a gap.
He has no idea whats going on around him nor what he should do about it.
How will he fare in this world?
For how long will he make it in a world where regular people may as well be bugs?
How will he cope with this situation?

(https://www.pixiv.net/en/artworks/50752377 This is the source for the image used in the cover I do not own it and do not claim to own it.)