Mysterious Encounters In My Neighborhood summary:

Something happens to Katagiri Jinpachi late one night when he unwittingly wanders into the youkai market. The only one who knows what it was seems to be one Harada Oriza, a famed painter of youkai portraits. But he is not talking, and Jinpachi only grows more frustrated and confused as he tries to return to the market and find out what he lost... or gained there.