Grave
There's a strange patch of dirt in this greenhouse that's actually a grave. Dig around a little and you'll find the marker buried in there. If you dig deeper you'll probably find less pleasant things.
ぼ
はか
None
You decide to dig even deeper into the grave out of curiosity and you find a bow (ぼ) and some arrows. This must be the grave of a great archer! But you probably shouldn't keep digging around in this grave looking for more stuff.