Growth

'Mana stones are extremely useful items.'

In workshops, they're used as materials for magical engineering; used directly, they restore mana, and sometimes they're even used to 'lure' or 'raise' monsters.

They aren't rare items, but they're useful in many ways, so both demand and supply are high.

[Mana Stones × 97]

I'd accumulated quite a few mana stones after hunting giant bats the previous night. I took one out and waved it in front of the harpy.

Gulp.

The creature showed interest, moving its throat dramatically. When I held out a pitch-black stone about the size of a finger joint, the harpy reflexively opened its mouth.

I popped it into the creature's mouth.

「?!」

The harpy's eyes immediately lit up. It sucked on it briefly as though it were a hard candy, then soon crunched it noisily before swallowing it...