Needing to do something to help the bath house get back in the black, Mayuko, Nenji and NieA go to the crater in search of an oil that rumor has it exists there.  Along the way, the group are attacked by giant plants and they lose their bento lunches.  When they return, they use the oil for the furnace and mix in some dead plants to cause a nice aroma.  All is well until the plants start growing.