On the first visit, there won't be any Pirori because of the Mouth Monster, so you'll have to encage the latter. That is done by setting up the cage with the Wood Plank, using the Red Eye as bait and luring the Beast there, quickly removing the plank so the cage will close.
The Pirori will then come out from their shelters again.
- Originally, the manhole cover in Shotengai connected to Pirori Village's well. This was changed with version 2.0.